I didn’t hear the phone. I ________ asleep.
| A．must be | B．must have been |
| C．should be | D．should have been |
A computer can’t remember who ; it simply does what .
| A．will use it; it is told | B．uses it; it has told |
| C．used it; it is told | D．has used it; it told |
Emergencies and unexpected situations happen all the time.
| A．may | B．can | C．must | D．should |
While watching television, .
| A．the doorbell rang | B．the doorbell rings |
| C．we heard the doorbell ring | D．we heard the doorbell rings |
The rising frequency for smoggy days puts me into deep that maybe one day citizens will have to rely on masks to survive.
| A．doubt | B．worry | C．shock | D．faith |
The report has found that more and more Chinese have an American or British temporary visa for holiday spending in recent years.
| A．stood for | B．applied for |
| C．accounted for | D．searched for |