Theo hoá trị của sắt trong hợp chất có CTHH là Fe2O3,hãy lập CTHH của hợp chất có phân tử gồm Fe và (SO4)

Cho CTHH của 2 chất:XO,YH3 (X,Y là những nguyên tố nào đó)
a)Hãy cho biết hoá trị của X,Y
b)Lập CTHH của hợp chất gồm 2 nguyên tố X,Y

Combine each of the following pairs of sentences into one sentence.

Using (NOT) ADJECTIVE + ENOUGH + TO INFINITIVE.

Choose the best answer to complete each sentence. 

1. In our science class today, Hoa _____ a new idea to save water. 

A. sent

B. received

C. came up with

D. transmitted

2. Will she be annoyed that you forgot to phone?

A. displeased

B. pleased

C. please

D. pleasure

3. The football match was _____ live on TV now. 

A. traveled

B. demonstrated

C. transmitted

D. arranged

4. She had to cook the dinner _____. 

A. myself

B. himself

C. herself

D. yourself

5. Come _____ and see the garden! 

A. outside

B. inside

C. insides

D. outsides

6. You can see a lot of famous paintings in this _____.

A. service

B. invention

C. demonstration

D. exhibition

7. Many students go to study in the library. We _____ talk in here. 

A. mustn't

B. don't have to

C. shouldn't to

D. needn't to

8. It's _____ to let children to play with cellphones for long. 

A. safes

B. safe

C. safely

D. unsafe

9. _____ is a thing that you use in the kitchen for storing food. 

A. Cooker

B. Cook

C. Refrigerator

D. Counter

10. The sun _____ in the East and _____ in the West. 

A. rises - set

B. sets - rises

C. rises -sets

D. set - rise

11. My family _____ from Vietnam to the USA when I was at the age of four. 

A. transmitted

B. conducted

C. immigrated

D. emigrated

12. Alexander Graham Bell was born _____ March 3, 1847. 

A. in

B. on

C. at

D. for

13. Mai loves children. She _____ a teacher when she is old enough. 

A. is

B. was

C. is going to become

D. was going

14. I _____ a letter from my friend today. 

A. sent

B. took

C. received

D. gave

Choose the best answer to complete each sentence. Write A, B, C or D after the number of each sentence on the answer sheet.

1. In our science class today, Hoa _____ a new idea to save water. *

A. sent

B. received

C. came up with

D. transmitted

2. Will she be annoyed that you forgot to phone?

A. displeased

B. pleased

C. please

D. pleasure

3. The football match was _____ live on TV now. *

A. traveled

B. demonstrated

C. transmitted

D. arranged

4. She had to cook the dinner _____. *

A. myself

B. himself

C. herself

D. yourself

5. Come _____ and see the garden! *

A. outside

B. inside

C. insides

D. outsides

6. You can see a lot of famous paintings in this _____. *

A. service

B. invention

C. demonstration

D. exhibition

7. Many students go to study in the library. We _____ talk in here. *

A. mustn't

B. don't have to

C. shouldn't to

D. needn't to

8. It's _____ to let children to play with cellphones for long. *

A. safes

B. safe

C. safely

D. unsafe

9. _____ is a thing that you use in the kitchen for storing food. *

A. Cooker

B. Cook

C. Refrigerator

D. Counter

10. The sun _____ in the East and _____ in the West. *

A. rises - set

B. sets - rises

C. rises -sets

D. set - rise

11. My family _____ from Vietnam to the USA when I was at the age of four. *

A. transmitted

B. conducted

C. immigrated

D. emigrated

12. Alexander Graham Bell was born _____ March 3, 1847. *

A. in

B. on

C. at

D. for

13. Mai loves children. She _____ a teacher when she is old enough. *

A. is

B. was

C. is going to become

D. was going

14. I _____ a letter from my friend today. *

A. sent

B. took

C. received

D. gave

một vật chịu tác dụng của lực F1=24N
a)Dưới tác dụng của lực F1 vật chuyển động như thế nào:Đều hay không đều.
b)Để vật chuyển động thẳng đều,người ta tác dụng lên vật lực F2 ngược hướng với F1.Tính độ lớn F2

một vật chịu tác dụng của lực F1=24N
a)Dưới tác dụng của lực F1 vật chuyển động như thế nào:Đều hay không đều.
b)Để vật chuyển động thẳng đều,người ta tác dụng lên vật lực F2 ngượic hướng với F1.Tính độ lớn F2

Complete the sentences with Preposition of Time

1. Mozart was born ______ Salzburg ______ 1756.  

2. They got married ______ April 2002.  

3. I'm usually free ______ 8 pm and 10 pm.  

4. What do you usually do ______ Sunday? - We often go for long walks in the country ______ weekends or ______ holidays.  

5. The course begins ______ 12 May and ends sometimes ______ August.  

6. She works hard ______ the week, so she likes relaxing ______ weekend.  

7. I'll leave ______ 7 o'clock, so you should call me ______ 7.  

8. My English class finishes ______ 7.30. Let's meet ______ 7.30.  

9. Do you give each other presents ______ Christmas?  

10. There are usually a lot of parties ______ New Year's Eve.  

11. He asked me to come ______ 11:30, not ______ noon.  

12. I suddenly felt ill ______ the examination.  

13. The book was easy to read, so I read it ______ a day.  

14. She started dancing ______ 8 and now she is a great star.  

15. Call me again ______ 11 o'clock because my classes will finish ______ 11:00.  

16. Did you phone your teacher the day ______ yesterday?  

17. My parents will get back from their holiday the day ______ tomorrow. 
18. Mr. Brown enjoys walking around his garden ______ night.  

19. Let's wait ______ it stops raining.  

20. He took a boat and reached the island ______ half an hour.  

21. My mother used to wear long dresses ______ special occasions.  

22. The bills always arrive ______ the first of the month.