Bird flu , a contagious disease of animals , is believed ____ by viruses that normally infect only birds and less commonly pigs , and rarely humans .
| A．caused | B．being caused | C．to be caused | D．to have caused |
二、单项选择
Don’t worry too much about ________ mistakes. They’re ________ natural part of learning something.
| A．the; the | B．/; the | C．the; / | D．/; a |
—We’d better go downstairs right now for lunch.
—__________ They serve food 24 hours a day.
| A．Hurry up! | B．Take your time. |
| C．No way! | D．It doesn’t matter. |
Nowhere else, as his mother told us, __________ except the cabin in the backyard.
| A．did he go | B．he did go | C．went he | D．he went |
We’re all ready to put it into operation, ____________, we’re going to take action as fast as possible.
| A．on the whole | B．in general | C．in conclusion | D．in other words |
—Your flight was quite late last night.
—Yes, it was midnight __________ our plane finally got to Jinan.
| A．that | B．when | C．since | D．until |