It was announced that only when the fire was under control ____ to return to their homes.
| A．the residents would be permitted | B．had the residents been permitted |
| C．the residents had been permitted | D．would the residents be permitted |
Some people would rather ride bikes as bike riding has _______ of the troubles of taking buses.
| A．nothing | B．none | C．some | D．neither |
In America, if _______ friend has invited you to drop i
n at any time, it is _______ best to call
before visiting to make sure it is convenient for him.
| A．a; a | B．the; a | C．a; 不填 | D．the; 不填 |
People in industrial countries take in _________as they actually need every day.
| A．twice as much protein | B．protein as much twice |
| C．twice protein as much | D．protein as twice as much |
To meet the challenge, the young people preferred _______ heavier work to do in their spare time.
A．to have  given |
B．to be giving | C．having give | D．to be given |
--- What has happened to Alice ?
--- I don’t know.
She__________her job.
| A．can have lost | B．may have lost | C．should have lost | D．need have lost |