Câu 3: Cho 4 lít N2; 14 lít H2 vào bình phản ứng hỗn hợp thu được sau phản ứng có thể tích 16,4 lít (đktc). Thành phần phần trăm về thể tích khí H2 trong hỗn hợp sau phản ứng là

A. 70,73%.                   B. 19,51%.                    C. 9,76%.                      D. 14,63%.

-2/x=-x/8

V. Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks.
SCHOOL UNIFORM
When I was a boy, children always objected to nearing school uniform, but teachers were keen (1) ……….… it because they said all of us looked alike. Otherwise, they said, children would complete with each other the poored children would be unhappy because people would see straight away what poor they were. In recent years, however, many schools have the idea of making children wear uniform but, funnily enough, now that children can (2) ……….…. what they like, they have adopted an own uniform. When some journalists visited a London school, they found that all the boys and girls were dressed (3) …….… jeans. One girl said she would rather die than wear a coat instead of a jersey because no one wants to look different (4) ……………. other children in the class. Parents may not be as happy about this as children, but they ought to be, because this new kind of uniform is one that the children like, not something ought to wear, and it’s also much cheaper than school uniforms much.
1. A. in                  B. out                C. on                  D. for (*)

2. A. play               B. go                 C. take                D. wear

3. A. to                   B. in                  C.on                   D.of

4. A. of                   B. from             C.into                  D.with

GIÚP VỚI SẼ VOTE 5 SAO 

Cho tam giác ABC cân tại A , trung tuyến AM , qua M kẻ đường thẳng song song AC cắt AB tại P và đường thẳng song song AB 

a) tứ giác APMQ là hình gì ?vì sao?

b) chứng minh PQ song song BC

Tính chất trung gian thể hiện ở vị trí,nhiệt độ trung bình năm,lượng mưa hằng năm như thế nào

20+2030-100(43+47-36)=