Tính thành phần % khối lượng các nguyên tố có trong hợp chất sau:

a)  Al2O3               b) Ca(HPO4)2

Giá trị của biểu thức Q=x(x - 2021) - y(2021 - x) tại x=3021 và y=-1994 là?

Match the questions in column A with the answer in column B for suitablesituations.

A

26. Shall we go out for dinner tonight?

27.Is 8 a.m OK?

28. Would you like to go to the cinema with me?

29. Can I speak to Nam please?

30. Let me help you do the housework?​

B

A. Yes, that's fine

B. That's a good idea

C. Certainly

D. That's very kind of you

E. Yes, I'd love to

Choose the best answer:
     He spends most of his time ____________volunteer work.

A. with doing 

B. did

C. doing 

D. to do