In many places of China, __________ bicycle is still __________ popular means of transportation.
| A．a; the |
| B．/; a |
| C．the; a |
| D．the; the |
At the eve of Christmas, she got nothing but $ 2 ____ to buy her husband a simple present.
| A．with what | B．which | C．what | D．with which |
_____ private cars bring us convenience, they also cause more traffic accidents and pollution.
| A．While | B．As | C．If | D．Since |
______ around the Water Cube , we were taken to see the Bird’s Nest for the 2008 Olympic Games.
| A．Having shown | B．To be shown | C．Having been shown | D．To show |
Her book didn’t ____ children probably because she employed too many scientific terms.
| A．appeal to | B．apply for | C．intend for | D．refer to |
After years of research, he found the key ____ differences between species.
| A．to explain | B．to explaining | C．of explaining | D．explaining |