The museum will open in the spring with an exhibition and a viewing platform ________ visitors can watch the big glasshouses being built. (2013·浙江，13)
| A．what | B．where |
| C．when | D．why |
________ by the problem that was put forward at the meeting, the people in the audience had ________ looks on their faces.
| A．Puzzled; puzzling | B．Puzzled; puzzled |
| C．Puzzling; puzzling | D．Puzzling; puzzled |
I ______ asleep because it took me a long time to realize that the telephone was ringing.
| A．could have fallen | B．should have fallen |
| C．must have fallen | D．mustn’t have fallen |
When she realized I _________ her, she quickly made a pose, smiling.
| A．was photographing | B．photographed |
| C．had photographed | D．will photograph |
Only when your identity has been checked _________.
| A．you are allowed in | B．you will be allowed in |
| C．will you allow in | D．will you be allowed in |
Don’t just sit there ________ your legs; come and help me carry the box upstairs.
| A．swung | B．to swing |
| C．swinging | D．and swinging |