As your instructor advised ,you ought to spend your time on something ______researching into .
| A．precious | B．worth | C．worthy | D．valuable |
His car ______ yesterday, so he can not go to work by car.
| A．is repaired | B．was repaired | C．repairs | D．has repaired |
The little boy has never been to Beijing, ________he ?
| A．haven’t | B．don’t | C．has | D．Does |
She _______ in Zhuzhou for ten years.
| A．will work | B．work | C．was working | D．has worked |
______ he did was quite right.
| A．What | B．Which | C． That | D．Who |
Nowadays, most young people enjoy ______ on the Internet.
| A．chat | B．to chat | C．chatting | D．chatted |