Whether at school or at home, children should be encouraged to read books and ______ what may be useful to their study.
| A．go down | B．settle down |
| C．break down | D．set down |
._____ nothing is doing ill.
| A．Do | B．To do | C．Doing | D．Does |
Our monitor talks about Mars as if he ______ a scientist.
| A．is | B．were | C．be | D．had been |
Your floor is dirty. It needs _______.
| A．clean | B．to clean | C．cleaning | D．cleaned |
. ---Here you go. There are______ such cards here.
--- I only need ______ these cards in the box.
| A．five dozens; one dozen | B．five dozens of; one dozen of |
| C．five dozen ; one dozen | D．dozens of ; one dozen of |
---Listen! The fire engine is roaring! (消防车吼叫)
--- Oh, there ______ be a fire somewhere. How terrible!
| A．should | B．must | C．have to | D．will |