1\Where can you go to buy beef ?

2\Who does Lan go to school with ?

3\How often do they go to the zoo ?

4\How much beef would you like ?

5\ How long is she going to stay there ?

6\ What do your daughters do every morning ?

7\ How much is this bar of soap ?

8\What colour are his pencils?

9\Where is Lan going to live ?

10\What are they going to paint ?

11\ How many English books do you want?

Hãy chỉ ra kết quả sai trong việc khử giá trị tuyệt đối của tích phân sau đây:  ∫ 0 2 π sinx d x

A.  ∫ 0 2 π sinx d x           B.  ∫ 0 π 2 sinx d x

C. ∫ 0 π sinx d x - ∫ π 2 π sinx d x           D. - ∫ π 2 π 2 sinx d x