Đốt cháy hoàn toàn 30 ml rượu etylic chưa rõ độ rượu, cho toàn bộ sản phẩm cháy đi vào dd Ca(OH)2 dư, thu được 100 g kết tủa. Biết khối lượng riêng của rượu etylic là 0,8g/ml và của nước là 1,0 g/ml. Độ rượu của rượu đem đốt là bao nhiêu?

1. I had finished lunch before my parents come. ……………. A B C D 2. By the time I had found the key, I hadn’t got into the house. ……………. A B C D 3.It was the last time my younger sister ever believed in love. ……………. A B C D 4. Mary just ate dinner so she wasn’t hungry. ……………. A B C D 5. When Bob graduated in university, he was in New York for 5 years. ……………. A B C D 6. Hundreds of houses destroyed after a tornado hit the small town of Texas. ……………. A B C D 7. Many people got injured in the storm because they weren’t prepared for the disaster. ……………. A B C D 8. It is reported that six people trapped in collapsed buildings have freed so far. ……………. A B C D 9. The earthquake occurred at midday when many people had had lunch. ……………. A B C D 10. Do you know that the word “tsunami” takes from the Japanese for “harbor wave”. …………….

1. David had gone home before we arrived. After ……………………………………………………………………………………. 2. The light had gone out before we got out of the office. When……………………………………………………………………………………. 3. After she had explained everything clearly, we started our work. By the time ……………………………………………………………………………. 4. My father had watered all the plants in the garden by the time my mother came home. Before …………………………………………………………………………………. 5.They provided food and then cleared up the debris. After they………………………………………….…………………………………………….. 6. My father had dinner, and then he watched a football match on TV. After………………………………………………………………………………………….. 7. She closed the door. She left the house. Before she………………………………………………………………………………………….. 8. Mary is cutting the cake with a sharp knife. The cake ………………………………………………………………………………………….. 9. The police haven’t found the murderer yet. The murderer ………………………………………………………………………………………….. 10. I don’t have enough time , so I can’t go on holiday this summer. If ……………………………………………………………………………………………………….

Em hãy viết một đoạn văn tả cảnh biển buổi sớm mai.

Cho hình thang ABCD (AB // CD) O là giao điểm của AC và DB.Dường thẳng qua O song song với AB cắt AD ở M.Chứng minh rằng: a) Tam giác OAB đồng dạng với tam giác OCD b) 1/OM = 1/AB + 1/CD

viết một đoạn văn chứng minh Bác Hồ sống giản dị (8-10 câu)

1. By the time he came home, we ……………… A. are sleeping B.had slept C. slept D.have sleep 2. I watched movie after I …………….my homework. A. have completed B. complete C. had completed D. completed 3. My father ……..out before my sister arrived in the zoo . A. goes B. will go C. has gone D. had gone 4. I ………a little English before I went to Singapore. A. study B. had studied C. studied D. have studied 5. Alice ________ a Vietnamese until she met Nam. A. had never met B. has never met C. never met D. never meets 6. After we …………. lunch, we took a look around the shops. A. had had B. had C. have had D. have 7. Where ………. she ……..…… before she moved to Shanghai? A. did - live B. had - lived C. had - live D. has - lived 8. After I ……….. my teeth, I went to bed, A. have brushed B. had brushed C. brushed D. brush 9. Before my mother came home, my brother…………. food on the table. A. had prepared B. has prepared C. prepared D. was preparing 10. It was the first time I………..sushi. A. have eaten B. ate C. had eaten D. eat

Mn hộ mk bài đó vs ạ, thay Mn Nhìu ạ

Mọi người giúp em bài 2 thôi ạ cả hai phần nhé giải chi tiết hộ em ạ em trân thành cảm ơn

Giúp mình với ạ!Giúp mình với ạ! 1. Yesterday, they (come) ………….. back home after they (finish) ………… their work. 2. She said that she ( meet) ……………………. Mr. Bean before. 3. Last night before he (go) ……………….. to bed, he (read) …………………… a novel. 4. When I came to the stadium, the match (start) ……………………………for a moment. 5. My father (not/ play) ……………………. any sports since last year. 6. Some people (attend) …………………….the meeting right now. 7. If I had a typewriter, I (type) ……………………. it myself. 8. He (live) ……………………. in Laos before he went to Vietnam. 9. After Hoa (eat) ……………………. the cake, she began to feel sick. 10. I (not drink) …………………….that wine if I (be) ……………………. you. 11. While the plumber (repair) ………………the dishwasher, I (watch) …………………the smartphone. 12. She said that she (already, see) .................................. Dr. Rice. 13. Yesterday, after he (take) ……………………. a bath, he (go) ......................... to bed. 14. He told me he (not/eat) ......................... such a kind of food before. 15. When he came to the station , the train (already/leave) ............................. 16. Yesterday, John (go) ....................... to the store before he (go) ....................... home. 17. She (win) ......................... the gold medal in 1986. 18. Our teacher (tell) ......................... us yesterday that he (visit) ......................... England before. 19. Before I (watch) ......................... TV, I had done my homework. 20. After I (wash) ......................... my clothes, I slept.