There are a lot of computers in the lab,and they need professional to make sure they can be in a good state.
| A．operation | B．maintenance |
| C．service | D．advice |
China has hundreds of islands, ___________ is Taiwan Island.
| A．among them the largest | B．and the largest of which |
| C．and the largest of them | D．but in which the largest |
You must have waited here for a long time ,___________you?
| A．mustn't | B．didn't | C．haven't | D．hadn't |
Nearly________ of the surface of our planet is covered by water.
| A．seven-ten | B．seven-tenth | C．seven-tenths | D．seventh-ten |
It's said that __________ is going to give us a lecture.
| A．an American famous young | B．a famous American youg |
| C．a famous young American | D．a young famous American |
----Would you please lend me the dictionary?
---- ____.
| A．You are welcome | B．Not at all | C．Thank you | D．Here you are |