—I wonder why Mr Green hasn't showed up at the meeting yet.
—I'm not sure，but he________in a traffic jam driving here.
| A．could be stuck | B．might have been stuck |
| C．might be stuck | D．must have been stuck |
______ a phone is of great help, I don’t think it’s a good idea to spend too much time on it.
| A．If | B．While | C．Because | D．As |
Peter will come to understand your efforts sooner or later. It’s just a matter of _____.
| A．luck | B．value | C．time | D．fact |
Experts think that __________recently discovered painting may be ________ Picasso.
| A．the ;不填 | B．the; a | C．a ;the | D．a ; 不填 |
The woman stayed at home to _____ her very sick child.
| A．tend | B．educate | C．refresh | D．advocate |
The mayor is strongly opposed to _____ a new hall, which may cost a lot of money.
| A．building | B．build | C．be building | D．have built |