You_________return the book now. You can keep it till next week if you like.
| A．needn’t | B．mustn’t | C．couldn’t | D．ought to |
----- Have you ______ some new ideas?
------ Yeah．I’ll tell you later.
| A．come about | B．come into | C．come up with | D．come out with |
Leave your key with a neighbor ______you lock yourself out one day．
| A．ever since | B．even if | C．soon after | D．in case |
A new_____ bus service to Tianjin Airport started to operate two months ago．
| A．normal | B．usual | C．regular | D．common |
----Do yon have a minute? I’ ve got something to tell you．
-----0K．______you make it short．
| A．now that | B．if only | C．so long as | D．every time |
Scientists are convinced--- the positive effect of laughter___ physical and mental health．
| A．of；at | B．by；in | C．of；on | D．on：at |