When I try to understand __________that prevents so many Americans from being as happy as one might expect, it seems that there are two causes.
| A．why it does | B．what it does | C．what it is | D．why it is |
A survey was carried out on the death rate of those who were infected by SARS,
________were surprising.
| A．as results | B．which results |
| C．the results of it | D．the results of which |
In recent years much more emphasis has been put______ developing the students productive
skills.
| A．onto | B．in | C．over | D．on |
_____ of water makes Death Valley a desert, but it is by no means devoid.
| A．Lacking | B．Being lack |
| C．Because of lack | D．Lack |
There are some police cars in front. What do you suppose _____?
| A．is the matter | B．is happened |
| C．is the wrong | D．the trouble is |
Tina _____ have known the truth, or she would have told us.
| A．mustn't | B．shouldn't | C．can't | D．needn't |