Exercise 1: Complete the story with the article “a/an/the”. 1. There was ________knock on ________door. I opened it and found ________small dark man in ________blue overcoat and _______woolen cap. 2. He said he was ________employee of ________gas company and had come to read ________meter. 3. But I had ________suspicion that he wasn't speaking ________truth because ________meter readers usually wear ________peaked caps. 4. However, I took him to ________ meter, which is in ________dark corner under ________ stairs. 5. I asked if he had ________ torch; he said he disliked torches and always read ________ meters by ________light of ________match. 6. I remarked that if there was ________leak in ________ gas pipe there might be ________ explosion while he was reading ________meter. 7. He said, “As ________matter of ________fact, there was ________explosion in ________last house I visited; and Mr. Smith, ________owner of ________house, was burnt in ________face.” 8. “Mr. Smith was holding ________lighted match at ________time of ________explosion.” 9. To prevent ________possible repetition of this accident, I lent him ________torch. 10. He switched on ________torch, read ________meter and wrote ________ reading down on ________back of ________envelope. Exercise 2: Choose the correct answers. 1. He didn't need______ out of his room in Moscow. a. go b. to going c. going d. to go 2. I could not ______ it even though I had wanted to do so. a. had bought b. buy c. buying d. have bought 3. I left my pen in this box, but it isn’t there now. Someone______ it. a. must have taken b. must take c. had to take d. had taken 4. Mary received 100 dollars from her sister. She______ the ring she wanted. It only costs 10 dollars. a. buys b. had bought c. bought d. might have bought 5. It lost my Honda last week; I hadn't locked it. You______ it. a. should lock b. should have locked c. ought to lock d. could lock 6. In 1900 the world had no deaths from rabies. Scientists______ wonderful vaccine. a. has discovered b. discovered c. must have discovered d. should have discovered 7. Mary received 100 dollars from her sister. She______ the computer she wanted. It costs 200 dollars. a. wouldn't buy b. hadn't bought c. couldn't have bought d. didn't buy 8. Once Helen failed in her exam. She played too much. She______ too much. a. shouldn't have played b. should play c. shouldn't play d. wouldn't have played 9. If I had liked that watch, may be I ______ bought it. a. will have b. must have c. would have d. shall have 10. Did my sister tell you that I had been to Dalat? a. might have b. could have c. would have d. must have 11. The women of this tribe______ precious ornaments for slat because they didn’t have any salt. a. have traded b. traded c. would have traded d. could trade 12. I took my only son to the park but he didn't like it. You ______ him to the zoo. a. should take b. had to take c. took d. should have taken 13. We are now wet. You______ the raincoats with you. a. should bring b. should have brought c. must bring d. have to bring 14. The yard is wet. It______ last night. a. must rain b. must have rain c. must have rained d. had to rain 15. Many birds will______ more than 3,000 miles to reach their winter homes. a. flying b. fly c. be fly d. flew

Giúp mik câu b câu c câu d vs ạ mik cảm ơn

Làm giúp mình với đang cần gấp ạ #chinhxac

y=1/3 x^3+(m+1)x^2 -(m+1)x+1 đồng biến R, Tìm m ?

đặt 10 câu với những cụm động từ Tiếng anh sau: ( mỗi 1 từ là một câu, ko cần phải đặt hết các từ) turn out, turn up, turn over, set off, throw away, call off, look forward to, look into, take after, dine out, run out of, break into, break through, pass away, live on, live by, live out, put away, put forward, put in, put in for, put off, tell of, face to.

Cho tam giác MPN vuông tại M( MP< MN). Trên cạnh MN lấy điểm Q sao cho MQ=MP, trên tia đối của tia MP lấy điểm R sao cho MR=MN. Chứng minh: a) PQ vuông góc NR, b) RQ vuông góc NP

Cùng một lúc một ô tô và một xe đạp khởi hành từ hai điểm A,B cách nhau 120m và chuyển động cùng chiều , ô tô đuổi theo xe đạp . Ô tô bắt đầu rời bến chuyển động nhanh dần đều với gia tốc 0,4m/s ², xe đạp chuyển động đều . Sau 40s ô tô đuổi kịp xe đạp . Xác định vận tốc xe đạp ( xem như chuyển đông đều) và khoảng thời gian cách hai xe sau thời gian 60s

Câu 9-16 ko cần làm nhé ai giúp mk với

Trên mặt nước vôi trong thường có lớp chất rắn trắng là canxi cacbonat tạo thành do canxi hidroxit trong nước vôi tác dụng với khí cacbonix trong không khí. Viết phương trình chữ của phản ứng

Giúp vs ạ! gấp.................