In freezing weather, snow can turn into ice, which is easy to ________.
| A．be slipped | B．slip |
| C．slip on | D．be slipping |
At school, some students are active ______ some are shy, yet they can be good friends with one another.
| A．while | B．although | C．so | D．as |
The new law states that people _______drive after drinking alcohol.
| A．wouldn't | B．needn't | C．won't | D．mustn't |
Sarah looked atfinished painting withsatisfaction.
| A．不填；a | B．a; the | C．the; 不填 | D．the; a |
------Did you go to the show last night?
------ Yeah． Every boy and every girl in the area ____ invited．
| A．were | B．was | C．has been | D．have been |
------ May I smoke here?
------ If you____, that's the smoking section over there.
| A．should | B．could | C．may | D．must |