35. I like getting up very early in summer. The morning air is so good ________.
| A．to be breathed | B．to breathe | C．breathing | D．being breathed |
21．It was not until dark ____ he found ____ he thought was the correct way to slove the problem.
| A．when; what | B．that; that | C．that; what | D．when; that |
20．—Though it is 30 years _____ we last met, I still remember the scene _____ we got separated on a rainy day.
| A．since; where | B．before; which | C．since; when | D．before; where |
19．—My cat’s really fat.
—You ______ have given her so much food.
| A．wouldn’t | B．couldn’t | C．mustn’t | D．shouldn’t |
18．—Jim, are you ______ this Saturday?
—Oh, sorry. I need to go to the bookshop _____ the bank on Saturday.
| A．convenient; and | B．convenient; as well as |
| C．available; as well as | D．available; with |
17．I _______there little more than a week when I set to work with the scientist.
| A．would be | B．had been | C．have been | D．will be |