It was in the supermarket I met Jenny yesterday.
| A．what | B．which | C．that | D．there |
—Where is Lu Wenjie? 
—I have no idea．He__________ be in the library.
| A．can | B．must | C．might | D．shall |
. — You must obey every word of mine!
— _____ I don’t?
| A．How if | B．What if | C．Even if | D．Only if |
16. The river,______the bank are covered with trees, is very long.
| A．whose | B．which | C．of which | D．which of |
While building a tunnel through the mountain, ________ .
| A．an underground lake was discovered |
| B．there was an underground lake discovered |
| C．a lake was discovered underground |
| D．the workers discovered an underground lake |
Lei Feng is always ready to help others when they are in trouble and he never ______ their request.
| A．turns up | B．turns over | C．turns in | D．turns down |