hòa tan 11,5 g na vào 500 g dd naoh có nồng độ 8% thu đc dd A.a, tính nồng độ % chất tan trong dd thu đc.b,để trung hòa dd A cần dùng bn ml dd X chứa đồng thời hcl 1M và h2so4 0,5M
Tính hóa trị của các nguyên tố sau: a) NaNO3 b) CuSO4 c) Al2O3 d) CuCl2
Hỗn hợp khí X gồm SO2 và O2 có tỉ khối so với CH4 là 3. Khối lượng của khí SO2 trong 9,6 gam hỗn hợp khí X là:
Cho hình thang ABCD ( AB // CD ) có góc B - góc C = 10 độ . Tính số đo góc B ?
Dạ anh chị nào đang rảnh vào hộ giá ạ
Exercise 3 1. It isn't worth while_______ her. a. marry b. to marry c. marrying d. to have married 2. She did nothing but_______ a. cry b. to cry c. to have cried d. crying 3. He can’t live without_______ here. a. being loved b. to love c. love d. loving 4. People are prevented from_______ to the polluted area. a. go b. going c. to go d. to have gone 5. Tourists are not allowed _______ in the Temple. a. to talk b. talk c. talking d. being talked 6. The teacher doesn't allow_______ dictionaries in the final examination. a. being used b. use c. using d. to use 7. Many countries have considered_______ the victims of the tsunami. a. to have helped b. to help c. help d. helping 8. The child admitted_______ a lie. a. tell b. telling c. to tell d. to be telling 9. The president agreed_______ the Agreement. a. to sign b. sign c. signing d. to have signed 10. The captain chose_______ with his ship. a. die b. to die c. to have died d. dying 11. Vietnam failed_______ Tiger Cup 2004! a. winning b. win c. to win d. to have won 12. The child promised_______ his parents. a. being obeyed b. obeying c. obey d. to obey 13. Lee was upset by_______ him the truth. a. our not having told b. us not tell c. we didn't tell d. not to tell 14. Wee considered_______ after work. a. to go shop b. going shopping c. going to shop d. to go to shop 15. Jack offered_______ care of my garden while I was out of town. a. take b. taking c. to have taken c. to take 16. Could you please come over? I need you _______ the refrigerator. a. help me moving b. helping me to move c. to help me move d. help me to move 17. I'll never forget_______ that race. What a thrill! a. to win b. win c. being won d. winning 18. No one has better qualifications. Carol is certain_______ for the job. a. to choose b. having chosen c. to be chosen d. being chosen 19. I was enjoying my book, but I topper_______ a program on TV. a. reading to watch b. to read to watch c. to read for watching d. reading for to watch 20. Who is the woman talking to Mr. Quinn? I don't recall_______ her around the office before. a. to have seen b. seeing c. to see d. being seen Exercise 4 1. He tried to avoid_______ my question. a. answer b. answering c. to answer d. to have answered 2. Paula has given up _______ to lose weight. a. try b. trying c. to try d. to have tried 3. We can't go on_______ like this. a. living b. live c. to live d. to be living 4. Don't keep_______ me while I'm talking. a. interrupt b. to interrupt c. interrupting d. to have interrupted 5. I can't imagine Bill _______ a motorbike. a. ride b. riding c. to ride d. to be riding 6. Sorry to keep you_______ so long. a. waiting b. wait c. to wait d. to have waited 7. She now regrets_______ it. a. say b. having said d. to say d. to have said 8. We decided_______ at home. a. to stay b. stay c. staying d. having stayed 9. Frank tends_______ too much. a. to have drunk b. drinking c. drink d. to drink 10. He doesn't want_______ a. to know b. know c. knowing d. to be knowing 11. I don’t advise anybody_______ in that hotel. a. stay b. to stay c. staying d. to have stayed 12. The mother made her child_______ the word a. repeat b. to repeat c. repeating d. to be repeating 13. My parents don't let me_______ out alone. a. go b. to go c. going d. to be going 14. I'm afraid I have some homework_______ today. a. do b. to do c. going d. done 15. Have the movers_______ the bedroom furniture first. a. brought in b. to bring in c. bring in d. bringing in 16. Do you know what_______ so many people evacuate their homes? a. forced b. made c. caused d. convinced 17. Where are the children? "I saw_______ in the yeard". a. them to play b. them playing c. they playing d. to them playing 18. You're been taking a lot of nice photographs. a. becoming b. about become c. to become d. about becoming 19. Jane's summer vacation in England led to_______ an English man. a. her marry b. her to marry c. her being married d. her marrying 20. We would like_______ to the president's reception, but we weren't a. having invited b. having been invited c. to have invited d. to have been invited
Nêu tác hại việc sd các chất kích thích và cháy nổ . thế nào là nhiễm AIDS HIV
1. Lan’ll have a party …………………. Friday evening. 2. Would you like to come ………. my house …………lunch? 3. She takes care …………. her family. 4. She works ………a local supermarket. 5. My mother works……………the field…………. my father. 6. Does your father work …………. . Hanoi? 7. David is good ………………. . Math. 8. What do you do …………. your free time? 9. Are you interested …………. . sports?. 10. There’s a good film …………. . ……… the moment. 11. Thanks ………. . your letter. 12. I’ll see my mom and dad ……………. . their farm. 13. We have to work hard ………. home and……………. school 14. We’ll visit her ………. Christmas. 15. Are you tired …………. . watching TV? 16. She often brings them …………… school. 17. He works ………. a factory. 18. We always go to Ha Long Bay ………. vacation. 19. Tell me more ………. . your family. 20. Can you send me a photo ………. . your family?
tìm GTNN GTLN a)MinA=(x+3y-5)^2 b)MaxB=(x+1)(2-x)(x-3)(x-6)
Giúp tui với mai nộp rồi 😫 Ai làm xong đầu tiên sẽ đc vote5sao+ cảm ơn nha ^^
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