Cho biểu thức :

\(C=\left(\dfrac{\sqrt{x}}{\sqrt{x}-1}-\dfrac{1}{x-\sqrt{x}}\right):\left(1+\dfrac{2}{\sqrt{x}-1}\right)\) 

a. Rút gọn C

b. Tìm x để C < -1

Rewrite the following sentences, beginning as shown and keep the meaning unchanged:

30. Somebody repaired her car yesterday.

- She

31. There was never any answer when we rang.

- Every

32. I can meet you if you arrive before eleven.

- So

33. My French friend finds driving on the left difficult.

- My French friend isn’t

34. They think the owner of the house is abroad.

- The owner

35. He could not afford to buy the car.

- The car

36. Although he had a good salary, he was unhappy in his job.

- In spite

37. He was annoyed because his secretary came late to work.

-He objected

38. I advise you to put your money in the bank.

- You’d

39. That restaurant is so dirty that no one wants to eat there.

- It is such

40. John only understood very little of what the teacher said.

- John could hardly

41. I’m sure you didn’t lock the front door. Here’s the key.

- You can’t

42. I haven’t been to Bristol for three years.

- The last time

43. Tim will be eighteen next week.

- It’s Tim’s

44. Unless he phones immediately he won’t get any information.

- If

45. How long is it since they bought the house?

- When

46. The garden still needs digging.

- The garden hasn’t

47. I am very pleased that we shall meet again soon.

- I am looking

48. My suit needs to be cleaned before the interview.

- I must

49. “You stole my best cassette, An!” Said Minh.

- Minh accused

50. This furniture is so old that it’s not worth keeping.

- This is

51. Although he didn’t speak Dutch, Bob decided to settle in Amsterdam.

- In spite

52. I’m sure it wasn’t Elton you saw because she’s in Bristol.

- It can’t

53. I would prefer you to deliver the sofar on Friday.

- I would rather

54. It is pointless to have that old typewriter repaired.

- That old typewriter is not

55. The bridge was so low the bus couldn’t go under it.

- It was

56. We’ve run out of tea.

- There

57. It is a six- hour drive from London to Edinburg.

- It takes

58. It is ages since Alan visited his parents.

- Alan

59. James spoke to his lawyer before signing the contract.

- James didn’t

60. They travelled across India, and then flew on to Japan.

- After

Rewrite the following sentences:

1.      He can’t go out because he has to study for his exam.
=> If…………………………………………………..

2.      She is lazy so she can’t pass the exam.
If…………………………………………………………

3.      He will pay me tonight; I will have enough money to buy a car.
=> If…………………………………………………………….

4.      He smokes too much; that’s why he can’t get rid of his cough.
=> If……………………………………………………………..

5.      She is very shy, so she doesn’t enjoy the party.
=> If……………………………………………………………..

6.      I will get a work permit. I will stay for another month.
=> If……………………………………………………………..

7.      He doesn’t take any exercises. He is so unhealthy
=> If……………………………………………………………….

8.      We can’t get the ticket because I don’t have the right change.
=> If………………………………………………………………..

9.      Study hard or you won’t pass the exam.
=> If…………………………………………………………………..

10.  Don’t be impatient or you will make mistakes.
=> If……………………………………………………………………..

11.  I didn’t eat lunch, I feel hungry now.
=> If I…………..………………………………….

12.  I only come if they invite me.
=> unless……………………………………………….

13.  He didn’t revise all his lessons, he failed the exam.
=> If he………………………………………………………..

14.  The park is over there, only 5 minutes’ walk.
=> If you walk……………………………………………….

15.  Leave me alone or I’ll call the police.

=>Unless……………………………………………………………………………………

16.  If you arrive at the office earlier than I do, please turn on the air-conditioner.

=> Should……………………………………………………………………………….     

17.  The children don’t go to school in the snowy weather.

=> If it ………………………………………………………………………………           

18.  He died so young; otherwise, he would be a famous musician by now.

=>Had ………………………………………………………………………………           

19.  You must tell me the whole truth or I won’t help you.

=> Unless………………………………………………………………………………       

20.  The car breaks down so often because you don’t take good care of it.

=> Were I………………………………………………………………………………

Choose the best option to complete each of the following sentences

1. If I ______ the bus this afternoon, I will get a taxi instead.

A. miss           B.will miss      C.missed         D.had missed

 2.`We’ll have to go without John if he ______ soon.

A.won't arrive            B.will arrive    C.arrives          D.doesn't arrive

 3.If you ______ your homework, I _____ you watch TV.

A.won't do/ let           B.did/ won't let            C.don't do/ won't let    D.won't do/ don't let

 4.If you _____ this switch, the computer _____ on.

A.press/ comes           B.will press/ comes     C.press/ can come       D.have pressed/ will comes

5.“Would you like some cake?”- “no thanks. If I ________ cake, I ______ fat.”

A.eat/ will get            B.ate/ would get          C.would eat/could get             D.am eating/ will get

6.Pam broke her arm in the accident. It____ much worse if she hadn't been wearing her seat belt.

A.will be        B.would have been     C.was  D.were

 7.“My boss made me work overtime again.”_ “if I _____ you, I _____ my job.”

A.were/ would have quit       B.am/ will quit C.was/ must quit         D.were/ would quit

 8.“I don't know whether to take that job or not”_“_____ you, I _____ it. ”

A.if I had been/ would have taken     B.should I be/ will take           C.if I were/would have taken

                                   D.I were/ would take

9.If you _____ me about the bad service, we'd have eaten there.

A.didn't tell    B.wouldn't have told   C.hadn't told    D.had told

10.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

11.If he ____ me, I'll be ready to help him.

A.ask             B.will ask        C.asks             D.to ask

12.When winter comes, I ____ a new coat.

A.buying                    B.buy              C.will buy                   D.buys

 13.What would Tom do if he ____ the truth?

A.would know           B.has know     C.knows          D.knew

14.If I ____ you, I wouldn't do that.

A.be               B.were             C.was              D.had been

15.If I had been absent from class yesterday, I____ the math test

A.would missed         B.would have missed              C.will miss                  D.miss

16.If I _____ a millionaire, I ______ a Civic Honda.

A.am/ will buy           B.was/ would buy       C.was/ would have bought     D.were/ would buy

17.“ Here is my phone number”- “thanks, I _______ you a call if I _____ some help.”

A.will give/ will need            B.would give/ needed             C.will give/ need         D.give/ need

18.If I _____ wings, I _____ take an airplane to fly home.

A.have/ won't have to            B.had/ wouldn't have to          C.have/ will have to    D.had/ didn't have to

19.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.

20.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.

21.______You work harder, you will be sacked.

A.Whether                 B.If                  C.However                 D.Unless

22.Unless you _____ quiet, I'll scream.

A.don't keep              B.keep             C.kept             D.didn't keep

23.I won't wake unless I ______ the alarm.

A.don't hear               B.heard            C.hear             D.didn't hear

 24.______, he would have been able to pass the exam.

A.If he studied more  B.If he were studying more     C.studying more          D.If he had studied more

 25.If I had had some more money, I _______ that book.

A.Would buy             B.will buy       C.would have bought              D.all are correct

26.______ if I take a map.

A.I will get lost          B.I will not get lost      C.I would get lost        D.I would not get lost

27.If cauliflowers ______ from extreme temperatures, the heads get discolored.

A.will not be protected          B.are not protected      C.were not protected   D.are not being protected

28.• ______ I have time, I will go with you,

A.If                B.Unless          C.So                D.So that

29.If you had told me that this was going to happen, I ___ it.

A.would never have believed            B.don’t believe            C.hadn’t believed        D.can’t believe

30.If Jake ___ to go on the trip, would you have gone?

A.doesn’t agree          B.didn’t agree              C.hadn’t agreed           D.wouldn’t agree

Rewrite the following sentences, beginning as shown and keep the meaning unchanged:

1. “Why don’t you complain to the company, Peter?” said William.

- William suggested

2. He started to play the guitar five years ago.

- He has

3. I am fond of my nephew although he behaves terribly.

- I am fond of my nephew in

4. “I wasn’t there at the time,” he said.

- He denied

5. “Who does that suitcase belong to?” the policeman asked us.

- The policeman asked us whose

6. She hasn’t ridden a horse before.

- It’s

7. We couldn’t answer those two difficult questions.

- Those two

8. Haven’t you got any cheaper televisions?

- Are these

9. I would prefer you not to smoke in here.

- I’d rather

10. The day was so cold that we stayed indoors.

- It was

11. She prefers reading to watching TV.

- She would

12. Eventually he succeeded in making her answer the question.

- Eventually he managed

13. Although he is intelligent, he doesn’t do well at school.

- In

14. I regret not going to the airport to say goodbye to him.

- I wish

15. She couldn’t get to work because of the heavy snow.

- The heavy snow

16. I had expected the weather to be worse.

-The weather was not

17. I didn’t arrive in time to see her.

- I wasn’t early

18. I’m sorry I was rude to you yesterday.

- I apologise

19.He didn’t hurry, so he missed the train.

- If

20. I haven’t seen that man here before.

- It’s

21. The furniture was so expensive that I didn’t buy it.

- The furniture was too

22. The robbers made the bank manager hand over the money.

- The bank manager

23. John has not had his hair cut for over six months.

- It is

24. You may get hungry on the train, so take some sandwiches.

- In

25. “I don’t think John will come,” said Bill.

- Bill doubted

26. We couldn’t drive because of the fog.

- The fog prevented

27. He failed to win the race.

- He didn’t

28. Mary rang hours and hours ago.

- It’s hours

29. Nobody can deny that she has a beautiful voice.

- It

30. Somebody repaired her car yesterday.

- She

Cho 0< a< π/2 thỏa mãn cot a = 8/15 . Tính sin a, cos a, tan a