China ______ the WTO for more than 10 years, and it has brought great changes to it.
| A．has joined | B．has been in | C．has become a member of | D．has joined in |
—Could you please ________us some stories?—OK.
A. say B. talk C. tell
My uncle says that it’s his duty ________the patients.
A. save B. to save C. Saving
As we know, ________ is good exercise and it is necessary for health.
A. walk B. walks C. walking
—Must I finish my homework before I go home?
—No, you ________. But you ________ finish it before tomorrow.
A.mustn’t, must
B. needn’t, must
C. needn’t, mustn’t
—Must we keep the window________ all the time? —No, you don’t have to.
A. open B. opened C. Opening