Phân tích 0,9 g A thu được 1,76 g CO2, 1,26 g nước, 224cm3 khí N ở đktc. Xác định công thức phân tử của A, bbieets tỉ khối của A đối với NO là 1,5.

20. The old man _________a black suit is a famous energy researcher. A. to wear B. wearing C. whom is wearing D.is wearing 21. Airplanes _________in the twentieth century is one of the sources of pollution. A. which invented B. to invent C. invented D. that is invented 22. We have an apartment_ ___________.the park A. overlooking B. overlooks C.to overlook D. overlooked 23. If energy _________ inexpensive and unlimited, many things in the world would be different. A. is B. will be C. would be D. were 24. Mohandas K. Gandhi, ______ Mahatma, lived a noble life of fasting and poverty in order to work for peace and independence. A. that was called B. was called C. called D. calling 25. Do you know the reason_______ she quit her job? A. that B. which C. when D. why 26. Alice: "What shall we do this evening?" – Carol: "______" A. No problem. B. Let’s go out for dinner. C. Oh, that’s good! D. I went out for dinner. Mark the letter A, B, C or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions. 27. Because power demand is increasing very rapidly, fossil fuels will be exhausted within a short time. A. enabled B. tired C. bushed D. used up Mark the letter A, B, C or D on your answer sheet to indicate the word(s) OPPOSITE in meaning to the underlined word(s) in each of the following questions. 28. Solar energy is not only plentiful and infinite but also clean and safe. A. unlimited B abundant C. limited D. rich Choose the word or phrase - a, b, c or d - that needs correcting. 29. In just (A) three months H.G. Wells wrote (B) the famous classic The Time Machine for what (C) he won a (D) Newberry Caldecott award. 30. Because much (A) species of plants and animals in Hawaii (B) ate threatened with (C) extinction within a short period of time, scientists are trying desperately (D) to rescue them. Choose the word or phrase among A, B, C or D which best fits each gap of the passage. We need energy to live and work. Our major source of…(31)……….is oil. Oil is one kind of fossil fuel. The amount of fossil fuel in the world is……(32)….Therefore, we must save it, and the same time, we must find new sources of energy. Geothermal heat and nuclear power are……(33)….sources of energy. They can give us electricity. Other alternative sources are the sun, waves and water. The sources are not only …(34)……and available but also clean and safe for the…(35)…People should develop and use them more and more in the future. 31. A. energy B. energetic C. energize D. energetically 32. A. limit B. limitation C. unlimited D. limited 33. A. alternative B. polluted C. harmful D. expensive

làm hộ e câu 6 em đang cần gấp

Cá muốn sống dc phải co khong khi ,nhung ta thay ca van song duoc duoi nuoc ,tai sao?

moi ngoi jup mik vs mik se vote5 s

Phương trình:2x² +mx-10=0 (m là tham số) có tổng hai nghiệm bằng 2010, thì m bằng

Giúp em câu này không chép mạng với ạ!!

Giúp mình phần bài tập nhannn mn

Giải hộ mình vs ạ mình cảm ơn nhiều ❤️

Bài 2: Một hình tam giác có độ dài đáy là 0,7m, chiều cao tương ứng với cạnh đáy là 3m. Tính diện tích hình tam giác? .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................. 1 Bài 3: Một đám đất hình thang có đáy lớn 66m và hơn đáy bé 18m. Chiều cao bằng 3 tổng hai đáy. Mùa vừa qua, người ta trồng lúa thu hoạch cứ 100m2 được 65kg lúa. Hỏi mùa vừa qua thu được mấy tấn lúa? .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................. .............................................................................................................................................................. Bài 4: Tính bằng cách thuận tiện: 7,03 : 0,2 + 7,03 : 0,25 – 7,03 × 2 + 7,03 : 0,5 + 7,03