a)cách 1(3/4+1/6)x2/3 cách 2( 3/4+1/6)x2/3 b)cách 1(5/9-1/2)x3/4 cách 2(5/9-1/2)x3/4

(2x -1/4y)(2x+1/4y) các bạn giải giúp

1895. Some scientists say it is essential that mankind _______ the amount of air pollution in big cities. A. be reduced B. reduced C. reduce D. will reduce 1896. She couldn‟t but _____ there crying. A. stood B. standing C. to stand D. stand 1897. ______ where to find the key, the boy could not open the safe. A. Knowing not B. Knew not C. Not knowing D. Didn‟t know 1898. They received _______ advice from their parents that they became successful. A. so good B. such a good C. so good an D. such good 1899. Computers are said to be _______ for the development of mankind. A. here to stay B. neither here nor there C. here and there D. here today, gone tomorrow 1900. _ “She‟s the best pianist in the school.” _ “__________” A. That‟s that. B. Never mind! C. That‟s OK! D. You can say that again. 1901. The river divides the city __________ two parts. A. with B. between C. by D. into 1902. When I was young, I __________ to smoke or drink. A. wasn‟t used B. didn‟t used C. never used D. not used 1903. “Would you mind turning the fan on?” - “__________.” A. Yes, please B. No, thank you C. Not at all D. No, I‟m not 1904. __________ he gets to the airport, he‟ll check in his luggage. A. Wherever B. However C. Although D. As soon as 1905. I‟d like to __________ a three minute call to London. A. make B. phone C. set D. do 1906. Your mother never let you cook the meals, __________? A. didn't she B. did she C. doesn't she D. does she 1907. I wondered __________ the right thing. A. whether I was doing B. whether I am doing C. whether was I doing D. if I am doing

viết 1 đoạn văn nghị luận xã hội khoảng 1 trang giấy thi trình bày suy nghĩ của em về người chiến sĩ áo trắng trong đại dịch covid-19

Mọi người giúp em với ạ. Em cảm ơn

mầm ikkkkkkkkkkkkkkkkkkkkkkkkk mn ơi đẹp thì mới cho hay nhất điều cẩm của hỏi:cấm ns từ chậm trong khi chủ hoi chưa cho phép

Chú Toàn mua một số thùng táo ở chợ đầu mối A để đi bán trong ngày. Buổi sáng chú bán đc 2/3 khối lượng táo đã mua. Nhưng buổi chiều chú chỉ bán đc 1/15 khối lượng táo đã mua. Hỏi sau 2 buổi đi bán số táo còn lại chiếm bn phần khối lượng táo đã mua.

Cho 59,4g Al td với dd HNO3 4M ta đc hh khí NO và N2O có tỉ khối hơn H2 là 18,5.Tính thể tích NO và N2O thu đc và thể tích dd HNO3

ai giúp em vs ạ ( em đăng 3 lần rồi í ạ 😢)

1881. By the time we get out of this traffic jam, all the guests _______ home. A. have gone B. had gone C. will go D. will have gone 1882. ______ members of the class has to be responsible for his own actions. A. Each of the B. Every C. None of D. All 1883. The teacher _______ them the answer to the question. A. explained B. said C. discussed D. told 1884. We met each other at the meeting ______ coincidence. A. by B. in C. for D. to 1885. As we‟ve been discussing for 2 hours without any solution, I‟d like to ______ my own solution to this problem. A. come up B. bring down C. put forward D. take in 1886. The accident resulted ______ some minor injuries. A. to B. from C. in D. of 1887. Dave, I really appreciate _______ me. But I think I could manage it myself. A. you to help B. you helped C. your helping D. that you would help 1888. One of the robbers was described by the witnesses _______ tall and about 25. A. like B. by C. in D. as 1889. I left the purse at home. Can you _______ without breakfast today, dear? A. go B. do C. make D. live 1890. One of the solutions _______ by environmentalists is to ban vehicles from the city center. A. are suggested B. is suggested C. suggesting D. suggested 1891. While the boss was away, her assistant stood ______ her and helped her solve any problems arising. A. up to B. in for C. up against D. out of 1892. I would like to rent a house, modern, comfortable, and _______ in a quite place. A. before all B. above all C. first of all D. after all 1893. We could never get ready for the test at such short _______. A. call B. notice C. advice D. note 1894. To resist corrosion _______ for today's car to prevent havoc caused by road salts, gravel and other materials. A. have new coatings been developed B. new coatings developing C. development of new coatings D. new coatings have been developed