Một gen có tỉ lệ A/G = 2/5 và có 2888 liên kết Hydro. Gen đó nhân đôi một số lần và đã phá vỡ 89528 liên kết Hydro.

a/ Tính số lần tự nhân đôi của gen.

b/ Tính số lươngj nuclêôtit từng loại chứa trong các gen con.

Rewrite the sentences so that they are nearest in meaning to the sentence printed before them .

1. Try hard and you can pass the examination.

-> If .........................................................................

2. The teacher said:" Don't talk in class"

-> The teacher ordered us..................................................

3. Mrs Huong said" chanh quan ! Why do you go to school late?"

->Mrs Hương asked ................................................

4. Tuong son said ," The sun rises in the East."

-> Tuong son said.................................................

Approximately 350 million people speak English as their first ___(1)___ . About the same number use it ___(2)___ a second language. It is the language ___(3)___ aviation, international sport and world trade. 75% of the world's mail is in English, 60% of the world's radio stations broadcast in English, and more than half of the world's newspapers are ___(4)___ in English. It is an official language in 44 countries. In ___(5)___ others, it is the language of business, commerce and technology. There are many varieties of English, but Scottish, Australian, Indian and Jamaican speakers of English, in spite of the differences in pronunciation, structure and vocabulary, would recognize that they are all speaking the same basic language.

11. Jim had to give up jogging because he had sprained his ankle severely.

→ Because of________________________________.

12. The water in most rivers is unsafe to drink because it’s polluted.

→ Because of________________________________.

13. We had to stay in London an extra day because it was foggy at the airport.

→ Because of________________________________.

14. Bill has to do all of the cooking and cleaning because his wife is ill.

→ Because of________________________________.

15. We all have received the best of everything because our parents are generous.

→ Because of________________________________.

16. I couldn’t get to sleep last night because it was noisy in the next apartment.

→ Because of________________________________.

17. John has to sit in the front row in class because he has poor eyesight.

→ Because of________________________________.

18. We stopped our car because the traffic lights turned red.

→ Because of________________________________.

19. She couldn’t see the road because the wall was too high.

→ Because of________________________________.

20. We postponed our trip because the driving conditions were bad.

→ Because of________________________________.

I, Combine the sentences using so….that
1. The weather was hot. You could fry an egg on the sidewalk
->
2. I couldn’t understand her. She talked too fast
->
3. Grandpa held me tightly when he hugged me. I couldn’t breathe for a moment
->
4. There were few people at the meeting. It was cancelled
->
5. Ted couldn’t get to sleep last night. He was worried about the exam
->
6. I can’t figure out what this sentence says. His handwriting is illegible
->
7. I have many problems. I can use all the help you can give me.
-> I
8. Jerry got angry. He put his fist through the wall
->
9. It took us only ten minutes to get there. There was little traffic
->
10. Too many people came to the meeting. There were not enough seats for everyone
->

II, Combine the sentences using “ such……that”
1. I don’t feel like going to class. We’re having beautiful weather
->
2. The classroom has comfortable chairs. The students find it easy to fall asleep
->
3. The Tornado struck with great force. It lifted automobiles off the ground
->
4. This is good coffee. I think I’ll have another cup
->
5. Karen is a good Pianist. I’m surprised she didn’t go into music professionally
->
6. It was good book. I couldn’t put it down
->
7. They were beautiful flowers. We took a photograph of them
->