Choose the correct words.
1. You mustn't / don’t have to / don’t must cheat in exams.
2. If you need help, you should to / need / should talk to your teacher.
3. I’m not thirsty, so I shouldn’t / don’t need / needn't to stop and have a drink.
4. You mustn't / don’t need / don’t have to do this extra homework. It’s your choice.
5. We must / have / need arrive on time to school every day.
6. Rosie has / have / need to catch the next bus.
1. mustn't
2. need
3. don't need
4. don’t have to
5. must
6. has
1. You mustn't cheat in exams.
2. If you need help, you should talk to your teacher.
3. I’m not thirsty, so I don’t need to stop and have a drink.
4. You don’t have to do this extra homework. It’s your choice.
5. We must arrive on time to school every day.
6. Rosie has to catch the next bus.
1. Fortunately, I .... working alone otherwise I would have got really bored at the night shift.
A) was supposed to
B) was to
C) was used to
D) would
E) used to
2. I don't think it was a good idea to intervene, instead, you .... your child to abandon the habit of thumb-sucking gradually, all by himself.
A) have allowed
B) had allowed
C) must have allowed
D) were able to allow
E) could have allowed
3. After the voyaging ship was wrecked during a storm at sea, unfortunately, only two of the men on board .... swim to the small island nearby.
A) might
B) were supposed to
C) could
D) were able to
E) had to
4. I don't know why she didn't ask me how to do it as I ---- her.
A) must have helped
B) could have helped
C) might help
D) should have helped
E) could help
5. Martin ---- my tennis racket without asking my permission. I got really angry with him.
A) needn't have taken
B) must not have taken
C) shouldn't have taken
D) didn't need to taken
E) might not have taken
6. I don't know why Peter is so late; do you think he ---- lost coming here?
A) may get
B) could get
C) must have got
D) might have got
E) was to have got
7. What ---- to Phil? He said he ---- here at eight o'clock.
A) might have happened / will be
B) should have happened / has been
C) may happen / will have been
D) would happen / is
E) can have happened / would be
8. One of the US national security advisers ---- there ---- better intelligence sharing before the September 11 attacks.
A) had acknowledged / can be
B) acknowledges / might be
C) has acknowledged / could have been
D) acknowledged / must be
E) would acknowledge / will have been
9. We all think that Maria ---- an interesting person to meet as we ---- a lot of stories about her so far.
A) is / had heard
B) can be / heard
C) might have been / hear
D) would be / have heard
E) will be / will have heard
10. As a young woman who had never given birth before, she ---- what the experience of childbirth ---- like.
A) doesn't know / will be
B) may not know / is
C) must not have known / will be
D) may not know / would be
E) couldn't have known / would be
1. Fortunately, I .... working alone otherwise I would have got really bored at the night shift.
A) was supposed to
B) was to
C) was used to
D) would
E) used to
2. I don't think it was a good idea to intervene, instead, you .... your child to abandon the habit of thumb-sucking gradually, all by himself.
A) have allowed
B) had allowed
C) must have allowed
D) were able to allow
E) could have allowed
3. After the voyaging ship was wrecked during a storm at sea, unfortunately, only two of the men on board .... swim to the small island nearby.
A) might
B) were supposed to
C) could
D) were able to
E) had to
4. I don't know why she didn't ask me how to do it as I ---- her.
A) must have helped
B) could have helped
C) might help
D) should have helped
E) could help
5. Martin ---- my tennis racket without asking my permission. I got really angry with him.
A) needn't have taken
B) must not have taken
C) shouldn't have taken
D) didn't need to taken
E) might not have taken
6. I don't know why Peter is so late; do you think he ---- lost coming here?
A) may get
B) could get
C) must have got
D) might have got
E) was to have got
7. What ---- to Phil? He said he ---- here at eight o'clock.
A) might have happened / will be
B) should have happened / has been
C) may happen / will have been
D) would happen / is
E) can have happened / would be
8. One of the US national security advisers ---- there ---- better intelligence sharing before the September 11 attacks.
A) had acknowledged / can be
B) acknowledges / might be
C) has acknowledged / could have been
D) acknowledged / must be
E) would acknowledge / will have been
9. We all think that Maria ---- an interesting person to meet as we ---- a lot of stories about her so far.
A) is / had heard
B) can be / heard
C) might have been / hear
D) would be / have heard
E) will be / will have heard
10. As a young woman who had never given birth before, she ---- what the experience of childbirth ---- like.
A) doesn't know / will be
B) may not know / is
C) must not have known / will be
D) may not know / would be
E) couldn't have known / would be
1. Fortunately, I .... working alone otherwise I would have got really bored at the night shift.
A. was supposed to
B. was to
C. was used to
D. would
E. used to
2. I don't think it was a good idea to intervene, instead, you .... your child to abandon the habit of thumb-sucking gradually, all by himself.
A. have allowed
B. had allowed
C. must have allowed
D. were able to allow
E. could have allowed
3. After the voyaging ship was wrecked during a storm at sea, unfortunately, only two of the men on board .... swim to the small island nearby.
A. might
B. were supposed to
C. could
D. were able to
E. had to
4. I don't know why she didn't ask me how to do it as I ---- her.
A. must have helped
B. could have helped
C. might help
D. should have helped
E. could help
5. Martin ---- my tennis racket without asking my permission. I got really angry with him.
A. needn't have taken
B. must not have taken
C. shouldn't have taken
D. didn't need to taken
E. might not have taken
6. I don't know why Peter is so late; do you think he ---- lost coming here?
A. may get
B. could get
C. must have got
D. might have got
E. was to have got
7. What ---- to Phil? He said he ---- here at eight o'clock.
A. might have happened / will be
B. should have happened / has been
C. may happen / will have been
D. would happen / is
E. can have happened / would be
8. One of the US national security advisers ---- there ---- better intelligence sharing before the September 11 attacks.
A. had acknowledged / can be
B. acknowledges / might be
C. has acknowledged / could have been
D. acknowledged / must be
E. would acknowledge / will have been
9. We all think that Maria ---- an interesting person to meet as we ---- a lot of stories about her so far.
A. is / had heard
B. can be / heard
C. might have been / hear
D. would be / have heard
E. will be / will have heard
10. As a young woman who had never given birth before, she ---- what the experience of childbirth ---- like.
A. doesn't know / will be
B. may not know / is
C. must not have known / will be
D. may not know / would be
E. couldn't have known / would be
1. Apple Computers ---- the share of the market held by Microsoft in the late 1990s but unfortunately they didn't have a clear business plan to more ambitiously pursue their business goals.
could capture
needn't have captured
should capture
might have captured
might capture
2. Many immigrants now agree that they ---- their traditions when they first settled in America.
shouldn't have given up
don't have to give up
may not have given up
might not give up
needn't give up
3. Although working conditions ---- in many occupations in the past few years, one can never be safe, particularly in places with higher risk occupations.
might improve
can't have improved
may have improved
could improve
needn't have improved
4. A good supervisor ---- with people who attempt too much than with those who try too little because hard-working staff contributes much to all aspects of work.
shouldn't work
would rather work
had better not work
is not able to work
can't work
5. If you want to get a good night's sleep, you ---- any tea or coffee in the evenings.
would rather drink
don't have to drink
mustn't drink
were able to drink
could drink
6. Road conditions ---- much in the last fifteen years, since the government hasn't invested anything to renew the roads.
must have improved
needn't have improved
didn't need to improve
ought to have improved
can't have improved
7. A new report suggests that a vaccine that offers at least partial protection against HIV ---- available in the near future.
had to be
could be
used to be
might have been
would rather be
8. He ---- technical support when his computer broke down because he doesn't know much about computers.
must have had
needn't have had
can't have had
didn't have to have
shouldn't have had
9. The new steam powered and mechanized farm equipment .... the work easier but they couldn't get it to work.
was able to make
can't have made
didn't have to make
might have made
had better make
10. If you plan to take a long trip in the car, you must get a full tank of gas or you ---- out of gas.
have to run
should have run
had better run
might run
are used to running
1. Apple Computers ---- the share of the market held by Microsoft in the late 1990s but unfortunately they didn't have a clear business plan to more ambitiously pursue their business goals.
could capture
needn't have captured
should capture
might have captured
might capture
2. Many immigrants now agree that they ---- their traditions when they first settled in America.
shouldn't have given up
don't have to give up
may not have given up
might not give up
needn't give up
3. Although working conditions ---- in many occupations in the past few years, one can never be safe, particularly in places with higher risk occupations.
might improve
can't have improved
may have improved
could improve
needn't have improved
4. A good supervisor ---- with people who attempt too much than with those who try too little because hard-working staff contributes much to all aspects of work.
shouldn't work
would rather work
had better not work
is not able to work
can't work
5. If you want to get a good night's sleep, you ---- any tea or coffee in the evenings.
would rather drink
don't have to drink
mustn't drink
were able to drink
could drink
6. Road conditions ---- much in the last fifteen years, since the government hasn't invested anything to renew the roads.
must have improved
needn't have improved
didn't need to improve
ought to have improved
can't have improved
7. A new report suggests that a vaccine that offers at least partial protection against HIV ---- available in the near future.
had to be
could be
used to be
might have been
would rather be
8. He ---- technical support when his computer broke down because he doesn't know much about computers.
must have had
needn't have had
can't have had
didn't have to have
shouldn't have had
9. The new steam powered and mechanized farm equipment .... the work easier but they couldn't get it to work.
was able to make
can't have made
didn't have to make
might have made
had better make
10. If you plan to take a long trip in the car, you must get a full tank of gas or you ---- out of gas.
have to run
should have run
had better run
might run
are used to running
1. You ---- the locksmith to open the door for you last night before you tried to open the door yourself.
must call
ought to have called
have had to call
could call
had better call
2. Scientists have found that people who are active at a moderate level experience a long list of health benefits and that physical activity ---- vigorous.
has to be
is not used to being
must be
had better be
needn't be
3. As well as being a popular tourist site, Trafalgar Square offers some of the most famous views in the country, ----?
has it
was it
doesn't it
hasn't it
didn't it
4. I ---- an office but I chose to work from home because everything I need is here.
could have rented
must have rented
may rent
might rent
needn't have rented
5. Climbers survive in this so-called death zone above eight thousand meters because they spend several months climbing to higher points on the mountain to ---- in those conditions.
used to live
have to live
would rather live
get used to living
had better live
6. You ---- down to about 30 kilometers an hour when you are driving through a school zone between dawn and dusk.
should have slowed
had to slow
were supposed to live
may have slowed
must slow
7. Most advanced aircraft now ---- at supersonic speeds.
could have fly
shouldn't have fly
are able to fly
had to fly
were supposed to fly
8. When an emergency vehicle is approaching with its lights and siren on, drivers ---- pull over and stop to get out of the way.
needn't have moved
must move
can't have moved
didn't need to move
must have moved
9. My girlfriend said I ---- her anything for her birthday, but I think I ---- her some flowers at least or a nice bottle of wine.
didn't need to buy / should buy
had to buy / can't have bought
should have bought / must buy
don't need to buy / don't have to buy
may not buy / may have bought
10. The prisoner ---- this way; there are no footprints at all.
may have escaped
needn't have escaped
could have escaped
had to escape
can't have escaped
1. You ---- the locksmith to open the door for you last night before you tried to open the door yourself.
must call
ought to have called
have had to call
could call
had better call
2. Scientists have found that people who are active at a moderate level experience a long list of health benefits and that physical activity ---- vigorous.
has to be
is not used to being
must be
had better be
needn't be
3. As well as being a popular tourist site, Trafalgar Square offers some of the most famous views in the country, ----?
has it
was it
doesn't it
hasn't it
didn't it
4. I ---- an office but I chose to work from home because everything I need is here.
could have rented
must have rented
may rent
might rent
needn't have rented
5. Climbers survive in this so-called death zone above eight thousand meters because they spend several months climbing to higher points on the mountain to ---- in those conditions.
used to live
have to live
would rather live
get used to living
had better live
6. You ---- down to about 30 kilometers an hour when you are driving through a school zone between dawn and dusk.
should have slowed
had to slow
were supposed to live
may have slowed
must slow
7. Most advanced aircraft now ---- at supersonic speeds.
could have fly
shouldn't have fly
are able to fly
had to fly
were supposed to fly
8. When an emergency vehicle is approaching with its lights and siren on, drivers ---- pull over and stop to get out of the way.
needn't have moved
must move
can't have moved
didn't need to move
must have moved
9. My girlfriend said I ---- her anything for her birthday, but I think I ---- her some flowers at least or a nice bottle of wine.
didn't need to buy / should buy
had to buy / can't have bought
should have bought / must buy
don't need to buy / don't have to buy
may not buy / may have bought
10. The prisoner ---- this way; there are no footprints at all.
may have escaped
needn't have escaped
could have escaped
had to escape
can't have escaped
1 we did not visit the museum because we had no time a if we have time , we will visit the museum b if we had time , we would visit the museum c if we had had time , we would have visited the museum d if we had had time , we will visit the museum 2 he looked frightened as if he ................ a ghost a sees b is seeing c has seen d had seen 3 ........... resigned , we would have been forced to sack him a had he not b had not he c he had not d he not had 4 if you ................ me about the bad service , we’d have eaten there a did not tell b would not have told c had not told d had told 5 the teacher was absent today, so class was canceled . if she ........... absent again tomorrow , class ........ tomorrow,too a is/will cancel b is / will be canceled c was / would be canceled d was/ would cancel 6 if you .................. to my advice in the first place , you............... in this mess right now a listen/will be b had listened / would not have been c will listened / would not be d had listened/ would not be 7 if i had been absent from class yesterday , i ............. the math test a would missed b would have missed c will miss d miss 8 if you ............... here earlier , you ............. her a had come / would have met b come / meet c came / would meet d comes will meet 9 i think you should stop smoking a if i am you , i will stop smoking b if i were you , i will stop smoking c if i were you , i would stop smoking d if i had been you , i would stop smoking 10 if i were , i would work harder a you would rather not work so hard c you should work harder c you should work with me d do not work so hard
1 we did not visit the museum because we had no time
a if we have time , we will visit the museum
b if we had time , we would visit the museum
c if we had had time , we would have visited the museum
d if we had had time , we will visit the museum
2 he looked frightened as if he ................
a ghost a sees b is seeing c has seen d had seen
3 ........... resigned , we would have been forced to sack him
a had he not b had not he c he had not d he not had
4 if you ................ me about the bad service , we’d have eaten there
a did not tell b would not have told c had not told d had told
5 the teacher was absent today, so class was canceled . if she ........... absent again tomorrow , class ........ tomorrow,too
a is/will cancel b is / will be canceled c was / would be canceled d was/ would cancel
6 if you .................. to my advice in the first place , you............... in this mess right now
a listen/will be b had listened / would not have been c will listened / would not be d had listened/ would not be
7 if i had been absent from class yesterday , i ............. the math test
a would missed b would have missed c will miss d miss
8 if you ............... here earlier , you ............. her
a had come / would have met b come / meet c came / would meet d comes will meet
9 i think you should stop smoking
a if i am you , i will stop smoking
b if i were you , i will stop smoking
c if i were you , i would stop smoking
d if i had been you , i would stop smoking
10 if i were , i would work harder
a you would rather not work so hard
b you should work harder
c you should work with me
d do not work so hard
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.
The idea of preserving biological diversity gives most people a warm feeling inside. But what, exactly, is diversity? And which kind is most worth preserving? It may be anathema to save-the-lot environmentalists who hate setting such priorities, but academics are starting to cook up answers.
Andrew Solow, a mathematician at the Woods Hole Oceanographic Institution, and his colleagues argue that in the eyes of conservation, all species should not be equal. Even more controversially, they suggest that preserving the rarest is not always the best approach. Their measure of diversity is the amount of evolutionary distance between species. They reckon that if choices must be made, then the number of times that cousins are removed from one another should be one of the criteria.
This makes sense from both a practical and an aesthetic point of view. Close relatives have many genes in common. If those genes might be medically or agriculturally valuable, saving one is nearly as good as saving both. And different forms are more interesting to admire and study than lots of things that look the same. Dr Solow’s group illustrates its thesis with an example. Six species of crane are at some risk of extinction. Breeding in captivity might save them. But suppose there were only enough money to protect three. Which ones should be picked?
The genetic distances between 14 species of cranes, including the six at risk, have already been established using a technique known as DNA hybridisation. The group estimated how likely it was that each of these 14 species would become extinct in the next 50 years. Unendangered species were assigned a 10% chance of meeting the Darwinian reaper-man; the most vulnerable, a 90% chance. Captive breeding was assumed to reduce an otherwise endangered species’ risk to the 10% level of the safest. Dr Solow’s computer permed all possible combinations of three from six and came to the conclusion that protecting the Siberian, white-naped and black-necked cranes gave the smallest likely loss of biological diversity over the next five decades. The other three had close relatives in little need of protection. Even if they became extinct, most of their genes would be saved.
Building on the work of this group, Martin Weitzman, of Harvard University, argues that conservation policy needs to take account not only of some firm measure of the genetic relationships of species to each other and their likelihood of survival, but also the costs of preserving them. Where species are equally important in genetic terms, and - an important and improbable precondition - where the protection of one species can be assured at the expense of another, he argues for making safe species safer, rather than endangered species less endangered.
In practice, it is difficult to choose between species. Most of those at risk - especially plants, the group most likely to yield useful medicines - are under threat because their habitats are in trouble, not because they are being shot, or plucked, to extinction. Nor can conservationists choose among the millions of species that theory predicts must exist, but that have not yet been classified by the biologists assigned to that tedious task.
This is not necessarily cause for despair. At the moment, the usual way to save the genes in these creatures is to find the bits of the world with the largest number of species and try to protect them from the bulldozers. What economists require from biologists are more sophisticated ways to estimate the diversity of groups of organisms that happen to live together, as well as those which are related to each other. With clearer goals established, economic theory can then tell environmentalists where to go.
[from The Economist]
Endangered species of cranes can be saved by _____________
A. stopping hunters from killing them
B. protecting their habitats
C. encouraging them to mate with their cousins
D. keeping them in zoos or wildlife parks
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.
The idea of preserving biological diversity gives most people a warm feeling inside. But what, exactly, is diversity? And which kind is most worth preserving? It may be anathema to save-the-lot environmentalists who hate setting such priorities, but academics are starting to cook up answers.
Andrew Solow, a mathematician at the Woods Hole Oceanographic Institution, and his colleagues argue that in the eyes of conservation, all species should not be equal. Even more controversially, they suggest that preserving the rarest is not always the best approach. Their measure of diversity is the amount of evolutionary distance between species. They reckon that if choices must be made, then the number of times that cousins are removed from one another should be one of the criteria.
This makes sense from both a practical and an aesthetic point of view. Close relatives have many genes in common. If those genes might be medically or agriculturally valuable, saving one is nearly as good as saving both. And different forms are more interesting to admire and study than lots of things that look the same. Dr Solow’s group illustrates its thesis with an example. Six species of crane are at some risk of extinction. Breeding in captivity might save them. But suppose there were only enough money to protect three. Which ones should be picked?
The genetic distances between 14 species of cranes, including the six at risk, have already been established using a technique known as DNA hybridisation. The group estimated how likely it was that each of these 14 species would become extinct in the next 50 years. Unendangered species were assigned a 10% chance of meeting the Darwinian reaper-man; the most vulnerable, a 90% chance. Captive breeding was assumed to reduce an otherwise endangered species’ risk to the 10% level of the safest. Dr Solow’s computer permed all possible combinations of three from six and came to the conclusion that protecting the Siberian, white-naped and black-necked cranes gave the smallest likely loss of biological diversity over the next five decades. The other three had close relatives in little need of protection. Even if they became extinct, most of their genes would be saved.
Building on the work of this group, Martin Weitzman, of Harvard University, argues that conservation policy needs to take account not only of some firm measure of the genetic relationships of species to each other and their likelihood of survival, but also the costs of preserving them. Where species are equally important in genetic terms, and - an important and improbable precondition - where the protection of one species can be assured at the expense of another, he argues for making safe species safer, rather than endangered species less endangered.
In practice, it is difficult to choose between species. Most of those at risk - especially plants, the group most likely to yield useful medicines - are under threat because their habitats are in trouble, not because they are being shot, or plucked, to extinction. Nor can conservationists choose among the millions of species that theory predicts must exist, but that have not yet been classified by the biologists assigned to that tedious task.
This is not necessarily cause for despair. At the moment, the usual way to save the genes in these creatures is to find the bits of the world with the largest number of species and try to protect them from the bulldozers. What economists require from biologists are more sophisticated ways to estimate the diversity of groups of organisms that happen to live together, as well as those which are related to each other. With clearer goals established, economic theory can then tell environmentalists where to go.
[from The Economist]
Three of the six species of endangered cranes _____________
A. were less interesting to admire than others
B. could be allowed to become extinct
C. were so rare they couldn’t be saved
D. shouldn’t be protected
Exer 1: Rewrite the sentence in the same meaning
1: Perhaps Susan know the address (may)
Susan .........................................................
2: it's possible that joanna didn't receive my message. (might)
joanna.....................................................................................
3: The report must be on my dest tomorrow.(has)
The report.........................................
4: I managed to finish all my work.(able)
I............................................................
5: It was not necessary for Nancy to clean the flat.(did not)
Nancy...................................................
6: The best thing for you to do í to sit down sit down.(better)
You...............................................................
Các bạn giúpmình với nhé!Xin cảm ơn
2Joanna might receive my address
1 Susan may know the address.
Gửi lại đề bài cho mình để mik làm cho
Câu 6 là Đề sai
5 Nancy did not have to clean the flat
4 I am able to finish all my work
3 The report has to be on my dest tomorrow
1:Susan may know the address.
2:Joanna might receive my message.
3:The report has to be on my dest tomorrow.
4:I am able to finish all my work.
5:Nancy did not have to clean the flat.
6:Nothing is better than sit down.(Câu này mà sai thì sorry nha!!!)
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.
The idea of preserving biological diversity gives most people a warm feeling inside. But what, exactly, is diversity? And which kind is most worth preserving? It may be anathema to save-the-lot environmentalists who hate setting such priorities, but academics are starting to cook up answers.
Andrew Solow, a mathematician at the Woods Hole Oceanographic Institution, and his colleagues argue that in the eyes of conservation, all species should not be equal. Even more controversially, they suggest that preserving the rarest is not always the best approach. Their measure of diversity is the amount of evolutionary distance between species. They reckon that if choices must be made, then the number of times that cousins are removed from one another should be one of the criteria.
This makes sense from both a practical and an aesthetic point of view. Close relatives have many genes in common. If those genes might be medically or agriculturally valuable, saving one is nearly as good as saving both. And different forms are more interesting to admire and study than lots of things that look the same. Dr Solow’s group illustrates its thesis with an example. Six species of crane are at some risk of extinction. Breeding in captivity might save them. But suppose there were only enough money to protect three. Which ones should be picked?
The genetic distances between 14 species of cranes, including the six at risk, have already been established using a technique known as DNA hybridisation. The group estimated how likely it was that each of these 14 species would become extinct in the next 50 years. Unendangered species were assigned a 10% chance of meeting the Darwinian reaper-man; the most vulnerable, a 90% chance. Captive breeding was assumed to reduce an otherwise endangered species’ risk to the 10% level of the safest. Dr Solow’s computer permed all possible combinations of three from six and came to the conclusion that protecting the Siberian, white-naped and black-necked cranes gave the smallest likely loss of biological diversity over the next five decades. The other three had close relatives in little need of protection. Even if they became extinct, most of their genes would be saved.
Building on the work of this group, Martin Weitzman, of Harvard University, argues that conservation policy needs to take account not only of some firm measure of the genetic relationships of species to each other and their likelihood of survival, but also the costs of preserving them. Where species are equally important in genetic terms, and - an important and improbable precondition - where the protection of one species can be assured at the expense of another, he argues for making safe species safer, rather than endangered species less endangered.
In practice, it is difficult to choose between species. Most of those at risk - especially plants, the group most likely to yield useful medicines - are under threat because their habitats are in trouble, not because they are being shot, or plucked, to extinction. Nor can conservationists choose among the millions of species that theory predicts must exist, but that have not yet been classified by the biologists assigned to that tedious task.
This is not necessarily cause for despair. At the moment, the usual way to save the genes in these creatures is to find the bits of the world with the largest number of species and try to protect them from the bulldozers. What economists require from biologists are more sophisticated ways to estimate the diversity of groups of organisms that happen to live together, as well as those which are related to each other. With clearer goals established, economic theory can then tell environmentalists where to go.
[from The Economist]
Most species are endangered because _____________.
A. biologists haven’t classified them
B. they are hunted or picked
C. we don’t care enough about them
D. the places they live in are being destroyed