Hai quả cầu mỗi quả có khối lượng 650kg, bán kính 6m đặt cách nhau 150m .Lực hấp dẫn giữa chúng lớn nhất bằng

Cho hai lực có độ lớn lần lượt là F1 = 8 N và F2 = 6 N. Độ lớn của hợp lực của chúng là F = 10 N. Góc giữa hai lực thành phần là

Giúp mình với

45.You  can use my car ………………..you drive carefully.

A.unless B. as long as C. as soon as D. when

46. If everyone……………….an extra hour a day, it would greatly increase production.

A. work B. works C. working D. worked

47. If energy…………………….inexpensive and unlimited, many things in the world would be different.

A.is B. were C. will be D. would be

48. Don't bother to ring me ………………….it's important.

A.unless B. in case C. if D. as

49.If you help me with this exercise, I …………….do the same for you one day.

A. will B. would C. was D. am

50. According to the timetable, if the train…………..on time, we………….arrive at 5.30.

A. leaves/ would B. left/ would C. leaves/ will D. was leaving/ would

51. If I could speak Spanish, I …………………..next year studying in Mexico.

A. will spend B. had spent

C. would spend D. would have spent

52. The bus won't stop ………………….you ring the bell.

A. if B. as soon as C.  providing D. unless

53. You'd  better  take a coat ………………..it gets cold.

A. if B. in case C. as long as D. while

54. If you ………………..to my advice in the first place, you wouldn't be in this mess right now.

A. listen B. will listen C. listened D. had listened

55. If it …………….fine tomorrow, we will go to the coast.

A. will be B. was C. is D. being

56. You …………..yourself ill if you don't eat properly.

A. were to make B. make C. would make D. will make

58. …………….more help, I can call my neighbour.

A.Should I need B. Needed

C. I have needed D. I should need

59.Come on! ……………….we hurry, we'll miss the plane!

A. if B. unless C. in case D. supposed

giúp mình với các bạn iu

please

45.You  can use my car ………………..you drive carefully.

A.unless B. as long as C. as soon as D. when

46. If everyone……………….an extra hour a day, it would greatly increase production.

A. work B. works C. working D. worked

47. If energy…………………….inexpensive and unlimited, many things in the world would be different.

A.is B. were C. will be D. would be

48. Don't bother to ring me ………………….it's important.

A.unless B. in case C. if D. as

49.If you help me with this exercise, I …………….do the same for you one day.

A. will B. would C. was D. am

50. According to the timetable, if the train…………..on time, we………….arrive at 5.30.

A. leaves/ would B. left/ would C. leaves/ will D. was leaving/ would

51. If I could speak Spanish, I …………………..next year studying in Mexico.

A. will spend B. had spent

C. would spend D. would have spent

52. The bus won't stop ………………….you ring the bell.

A. if B. as soon as C.  providing D. unless

53. You'd  better  take a coat ………………..it gets cold.

A. if B. in case C. as long as D. while

54. If you ………………..to my advice in the first place, you wouldn't be in this mess right now.

A. listen B. will listen C. listened D. had listened

55. If it …………….fine tomorrow, we will go to the coast.

A. will be B. was C. is D. being

56. You …………..yourself ill if you don't eat properly.

A. were to make B. make C. would make D. will make

20. You won’t pass the examination……………you study more.

a. as long as b. unless c. if d. whether.

21. ………………. in your position, I would have another check.

a. If I am b. Unless I was c. Were I d. Was I

22. If I were to leave my country , I ……………disappointed.

a. probably be b. would have been      c. will be d. would be.

25. If I were in your place, I ……….a trip to England.

a. will make b. had made c. made. d. would make.

26. If I  ………….. you , I’d save some of your lottery winning.

a. be b. were c. am d. was

28. If I had enough money, I ……… abroad to improve my English.

a. will go b. should go c. would go d. should have go to

30.Keep silent ……….. I will sent you out.

a. If b. unless c. provided that d. or

32. Trees won’t grow ……….. there is enough water.

a. if b. when c. unless d. as

33. If you ………. to my advice in the first place, you wouldn’t be in this mess right now.

a. listen b. had listened c. will listen d. listened

35. If someone ……… into the store, smile and say, “ May I help you?”

a. comes b. came c. would come d. could lend

36.We'll have lunch outside in the garden …………….it's too cold.

A. if B. unless C. in case D. should

37.John………………………win more races if he trained harder.

A. would B. will C. would have D. shall

38.If the machine………………….., press this button.

A. stop B. stops C. would stop D. stoped

40. I can't understand what he sees in her! If anyone treated me like that, I …………….extremely

angry!

A. am B. would be C. will be D. was

41. If you…………….up all the orange juice that was in that carton, you ought to go out and get

some more.

A. drank B. drinking C. drunk D. drink

42. Rachel will be pleased…………….she passes her driving test.

A. should B. will C. if D. unless

44. Ifyou can give me one good reason for your acting like this,  ……………….this incident again.

A. I don't mention B. I will never mention

20. You won’t pass the examination……………you study more.

a. as long as b. unless c. if d. whether.

21. ………………. in your position, I would have another check.

a. If I am b. Unless I was c. Were I d. Was I

22. If I were to leave my country , I ……………disappointed.

a. probably be b. would have been      c. will be d. would be.

25. If I were in your place, I ……….a trip to England.

a. will make b. had made c. made. d. would make.

26. If I  ………….. you , I’d save some of your lottery winning.

a. be b. were c. am d. was

28. If I had enough money, I ……… abroad to improve my English.

a. will go b. should go c. would go d. should have go to

30.Keep silent ……….. I will sent you out.

a. If b. unless c. provided that d. or

32. Trees won’t grow ……….. there is enough water.

a. if b. when c. unless d. as

33. If you ………. to my advice in the first place, you wouldn’t be in this mess right now.

a. listen b. had listened c. will listen d. listened

35. If someone ……… into the store, smile and say, “ May I help you?”

a. comes b. came c. would come d. could lend

36.We'll have lunch outside in the garden …………….it's too cold.

A. if B. unless C. in case D. should

37.John………………………win more races if he trained harder.

A. would B. will C. would have D. shall

38.If the machine………………….., press this button.

A. stop B. stops C. would stop D. stoped

40. I can't understand what he sees in her! If anyone treated me like that, I …………….extremely

angry!

A. am B. would be C. will be D. was

41. If you…………….up all the orange juice that was in that carton, you ought to go out and get

some more.

A. drank B. drinking C. drunk D. drink

42. Rachel will be pleased…………….she passes her driving test.

A. should B. will C. if D. unless

44. Ifyou can give me one good reason for your acting like this,  ……………….this incident again.

A. I don't mention B. I will never mention