Exercise 1. Choose the best answer to complete the following sentences. 21. If I ………..a camera, I would have taken some pictures. a. have b. had c. would have d. had had. 22. You won’t pass the examination……………you study more. a. as long as b. unless c. if d. whether. 23. If only I …………you wanted to invest money in business. a. had known b. knew c. have known d. know. 24. If I were to leave my country , I ……………disappointed. a. probably be b. would have been c. will be d. would be. 25. If he hadn’t wasted too much time, he…………….in his examination. a. would fail b. wouldn’t fail c. wouldn’t have failed. d. won’t fail. 26. If I had taken that English course, I ………..much progress. a. had made b. would have made c. made d. would make. 27. If I were in your place, I ……….a trip to England. a. will make b. had made c. made. d. would make. 28. If I ………….. you , I’d save some of your lottery winning. a. be b. were c. am d. was 29. If the car ……….. larger, we would have bought it. a. had been b. have been c. has been d. been 30. 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 31. If it …….. convenient, let’s go out for a drink tonight. a. be b. was c. were d. is 32. If you ……. time, please write to me. a. have b. have had c. had d. has 33. If you had the chance, ………… you go finishing? a. did b. would c. may d. do 34. Trees won’t grow ……….. there is enough water. a. if b. when c. unless d. as 35. 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 36. I wish I …….. you some money for your rent, but I’m broke myself. a. can lend b. could lend c. would lend d. will lend 37. If someone ……… into the store, smile and say, “ May I help you?” a. comes b. came c. would come d. could lend 38. If you stay up late the previous night, you ………. sleepy the next morning. a. feel b. to feel c. feels d. will feel 39. If Peter ………., Sarah will be sad because she wants to meet him very much a. comes b. do not come c. does not come d. will come 40. If his teeth still …….., he will have to go to the dentist’s again. a. hurt b. hurts c. to hurt c. will hurt 41. If you…………Tom , tell him I have a message for him. a. will meet b. would meet c. meet d. met 42. If you …………too hot during the night , turn down the central heating.

phân tích đa thức thành nhân tử:phương pháp 2 (a+b)^3-c^3 125-(x+2)^3 (x+3)^3-8 x^6-1 X^6+1 (x-y)^3-(x+y)^3

Giúp em hóa với mn 👇👇👇👇🙏 (14,15,16)🙏

Giúp mình ý a thôi nha, thank các you nhiều

Bài 1: 1. I (learn) English for seven years now. 2. But last year I (not/ work) hard enough for English, that's why my marks (not/ be) really that good then. 3. As I (pass/ want) my English exam successfully next year, I (study) harder this term. 4. During my last summer holidays, my parents (send) me on a language course to London. 5. It (be) great and I (think) I (learn) a lot. 6. Before I (go) to London, I (not/ enjoy) learning English. 7. But while I (do) the language course, I (meet) lots of young people from all over the world. 8. There I (notice) how important it (be) to speak foreign languages nowadays. 9. Now I (have) much more fun learning English than I (have) before the course. 10. At the moment I (revise) English grammar. 11. And I (begin/ already) to read the texts in my English textbooks again. 12. I (think) I (do) one unit every week. 13. My exam (be) on 15 May, so there (not/ be) any time to be lost. 14. If I (pass) my exams successfully, I (start) an apprenticeship in September. 15. And after my apprenticeship, maybe I (go) back to London to work there for a while. 16. As you (see/ can), I (become) a real London fan already. Bài 2: Chọn đáp án đúng nhất 1. When I last saw him, he _____ in London. A. has lived B. is living C. was living D. has been living 2. We _______ Dorothy since last Saturday. A. don't see B. haven't seen C. didn't see D. hadn't seen 3. The train ______ half an hour ago. A. has been leaving B. left C. has left D. had left 4. Jack ______ the door. A. has just painted B. paint C. will have painted D. painting 5. My sister ________ for you since yesterday. A. is looking B. was looking C. has been looking D. looked 6. I ______ Texas State University now. A. am attending B. attend C. was attending D. attended 7. He has been selling motorbikes ________. A. ten years ago B. since ten years C. for ten years ago D. for ten years 8. Christopher Columbus _______ American more than 500 years ago. A. discovered B. has discovered C. had discovered D. had been discovering 9. He fell down when he ______ towards the church. A. run B. runs C. was running D. had run 10. We _______ there when our father died. A. still lived B. lived still C. was still lived D. was still living 11. They ______ table tennis when their father comes back home. A. will play B. will be playing C. play D. would play 12. By Christmas, I _______ for Mr. Smith for six years. A. will have been working B. will work C. have been working D. will be working 13. I _______ in the room right now. A. am being B. was being C. have been being D. am 14. I ______ to New York three times this year. A. have been B. was C. were D. had been 15. I'll come and see you before I _______ for the States. A. leave B. will leave C. have left D. shall leave 16. The little girl asked what _______ to her friend. A. has happened B. happened C. had happened D. would have been happened 17. John ______ a book when I saw him. A. is reading B. read C. was reading D. reading 18. He said he _______ return later. A. will B. would C. can D. would be 19. Jack ________ the door. A. has just opened B. open C. have opened D. opening 20. I have been waiting for you ______. A. since early morning B. since 9 a. m C. for two hours D. All are correct 21. Almost everyone _______ for home by the time we arrived. A. leave B. left C. leaves D. had left 22. By the age of 25, he ______ two famous novels. A. wrote B. writes C. has written D. had written 23. When her husband was in the army, Mary ______ to him twice a week. A. was reading B. wrote C. was written D. had written 24. I couldn't cut the grass because the lawn mower ______ a few days previously. A. broke down B. has been broken C. had broken down D. breaks down 25. I have never played badminton before. This is the first time I _____ to play. A. try B. tried C. have tried D. am trying 26. Since _______, I have heard nothing from him. A. he had left B. he left C. he has left D. he was left

Các bạn và các anh chị giúp e làm bài 8 và 9 vs ạ

với a+b+c=1. cmr P =√3(ab)+√3(bc)+√3(ac)<=√3(3)

Khi thực hiện hoạt động để hình thành kiến thức mới trong bài học, học sinh sẽ được sử dụng những thiết bị dạy học/ học liệu nào?

1. Kim loại chứa tất cả các gốc muối đều tan? 2. Muối tan trong nước? 3. Muối không tan trong nước? 4. Độ tan là gì? 5. Độ tan của chất rắn phụ thuộc vào? 6. Bazo không tan? 7. Axit không tan trong nước?

Ực.... hình như tôi chiều các em quá rùi các em hư phải hông vẽ anime nam đang buồn ngủ ( vẽ full người ) nhưng miễn các em thích... Ực... các em có thể vẽ nửa người