In the event of an earthquake, you mustn’t go panicking.     

-> If in the event of an earthquake , you shouldn't go panicking.                    

19- If you don’t leave the office, I will call the police (or).

=> Leave the office or I will call the police.

20- If I didn’t say sorry, I wouldn’t be here (otherwise).

=>I say sorry, otherwise, I wouldn’t be there.

21, If it weren’t for the view, this would be a lovely roon ( But for).

=>But for the view, this would be a lovely room.

22, The ground was very soft. But for that, my horse would have won (If).

=>If the ground hadn't been too soft, my horse would have won

23, But for his quickness I had been killed (If).

=>If he hadn't been quick, I would have been killed.

EM LÀM CHƯA RÀNH PHẦN IF NÀY LẮM AI XEM GIÚP EM VỚI SỬA GIÚP EM VỚI Ạ HUHU

12 sai, C mới là đáp án đúng 

13 sai, A đúng, \(sin-sin=2cos...sin...\)

18.

\(\Leftrightarrow\left\{{}\begin{matrix}a=m>0\\\Delta'=m^2-m\left(-m+3\right)< 0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}m>0\\2m^2-3m< 0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}m>0\\0< m< \dfrac{3}{2}\end{matrix}\right.\) \(\Rightarrow m=1\)

Đáp án B

22.

Để pt có 2 nghiệm pb \(\Leftrightarrow\left\{{}\begin{matrix}m-2\ne0\\\Delta'=\left(2m-3\right)^2-\left(m-2\right)\left(5m-6\right)>0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}m\ne2\\-m^2+4m-3>0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}m\ne2\\1< m< 3\end{matrix}\right.\)

Theo hệ thức Viet: \(\left\{{}\begin{matrix}x_1+x_2=\dfrac{-2\left(2m-3\right)}{m-2}\\x_1x_2=\dfrac{5m-6}{m-2}\end{matrix}\right.\)

\(\dfrac{-2\left(2m-3\right)}{m-2}+\dfrac{5m-6}{m-2}\le0\)

\(\Leftrightarrow\dfrac{m}{m-2}\le0\) \(\Leftrightarrow0\le m< 2\)

Kết hợp điều kiện delta \(\Rightarrow1< m< 2\)

24.

Đề bài câu này dính lỗi, ko có điểm M nào cả, chắc là đường thẳng đi qua A

Đường tròn (C) tâm I(1;-2) bán kính R=4

\(\overrightarrow{IA}=\left(1;3\right)\)

Gọi d là đường thẳng qua A và cắt (C) tại 2 điểm B và C. Gọi H là trung điểm BC

\(\Rightarrow IH\perp BC\Rightarrow IH=d\left(I;d\right)\)

Theo định lý đường xiên - đường vuông góc ta luôn có: \(IH\le IA\)

Áp dụng Pitago cho tam giác vuông IBH: 

\(BH=\sqrt{IB^2-IH^2}\Leftrightarrow\dfrac{BC}{2}=\sqrt{16-IH^2}\)

\(\Rightarrow BC_{min}\) khi \(IH_{max}\Leftrightarrow IH=IA\)

\(\Leftrightarrow IA\perp d\Rightarrow d\) nhận \(\overrightarrow{IA}\) là 1 vtpt

Phương trình d: 

\(1\left(x-2\right)+3\left(y-1\right)=0\Leftrightarrow x+3y-5=0\)

1. A. celebrate             B. together            C. restaurant         D. organize

2. A. pollution              B. awareness        C. disappear          D. addition

3. A. apple                   B. butter                C. mother               D. advance

4. A. protection            B. referee              C. dictation             D. increasing

5. A. carriage               B. damage            C. survive               D. lightning

6. A. generosity            B. occurrence       C. priority               D. memorial

1. A. celebrate             B. together            C. restaurant         D. organize

2. A. pollution              B. awareness        C. disappear          D. addition

3. A. apple                   B. butter                C. mother               D. advance

4. A. protection            B. referee              C. dictation             D. increasing

5. A. carriage               B. damage            C. survive               D. lightning

6. A. generosity            B. occurrence       C. priority               D. memorial

1.A

2.B

3.B

4.C

5.C

6.D

7.A

8.D

9.B

10.B

11.B

12.C

13.B

14.B

15.B

Câu 43: would you have visited

Câu 44: gave

Câu 45: would buy

Câu 46: cleaned

Câu 47: would you be able

Câu 48: didn't belong

Câu 49: won 

Câu 50: would you do 

Câu 51: knew

Câu 52: gave

Câu 53: stopped

Câu 54: wouldn't come

Câu 55: saw

Câu 56: would be

Câu 57: wouldn't be

Câu 58: had

Câu 59: did

Câu 60: would grow

43 If I were sent to prison, would you (visit) visit me?

44 If someone (give) …………gave……… you a helicopter, what would you do with it?

45 I (buy) …………would buy…… shares in that company if I had some money.

46 If he (clean) ………cleaned……… his windscreen he'd be able to see where he was going.

47 If you drove your car into the river, would you (be able) ……be able.. to get out?

48 If you (not belong) ………didn't belong………to a union, you couldn't get a job.

49 If I (win………won…………) a big prize in a lottery, I'd give up my job.

50 What …would……you (do)…do…… if you found a burglar in your house?

51 I could tell you what this means if I (know) ………knew…………Greek.

52 If everybody (give) ………gave…………Ј1, we would have enough.

53 He might get fat if he (stop) …………stopped……… smoking.

54 If he knew that it was dangerous he (not come). ………wouldn't come…………

55 If you (see) ………saw………someone drowning what would you do?

56 I (be) ………would be………ruined if I bought her everything she asked for.

57 If you slept under a mosquito net you (not be) …………wouldn't be………bitten so often.

58 I could get a job easily if I (have) ………had…………a degree.

154 If she (do) ………did……her hair differently she might look quite nice.

59 If we had more rain our crops (grow) …………would grow……… faster. 

60 If you (arrive) …had arrived…ten minutes earlier you would have got a seat.

61 You would have seen my garden at its best if you (be) …………had been……… here last week.

62 I shouldn't have believed it if I (not see) …hadn't seen… it with my own eyes.

63 If he had slipped he (fall) …………would have fell………500 meters.

64 If he had asked you, ……would………you (accept) …………have accepted………?

65 If I (had) …………had had……… a map I would have been all right.

 66 If I (know) ……had known…… that you were coming I'd have baked a cake.

 67 I (offer) ………would have offered……… to help him if I had realized that he was ill.

68 If you had left that wasp alone it (not sting) ………wouldn't have stung…………you.

69 If I (realize) …………had realized………what a bad driver you were I wouldn't have come with you.

70 If I had realized that the traffic lights were red I (stop) ………would have stopped…….

71 If you had told me that he never paid his debts I (not lend) …………would have lent………him the money.

72 If you (not sneeze) …………hadn't sneezed………he wouldn't have known that we were there.

73 If you (put) …………had put……… some mustard in the sandwiches they would have tasted better.

74 The hens (not get) ……wouldn't have got… into the house if you had shut the door.

75 If he had known that the river was dangerous he (not try) …………wouldn't have tried……… to swim across it. 

76 If you (speak) ……had spoken…more slowly he might have understood you.

77 If he had known the whole story he (not be) ………wouldn't have been……so angry.

78 I shouldn't have eaten it if I (know) …had known…that there was ginger in it.

79 If I (try) ………had tried………… again I think that I would have succeeded.

80 You (not get) …wouldn't have got… into trouble if you had obeyed my instructions.

81 If you hadn't been in such a hurry you (not put) …………wouldn't have put………sugar into the sauce instead of salt.

82 If I (be) …………had been………ready when he called he would have taken me with him.

83 She had a headache; otherwise she (come) ………would come have………with us.

84 If she had listened to my directions she (not turn) ………wouldn't have turned………… down the wrong street.

85 If you (look) …………had looked………at the engine for a moment you would have seen what was missing.