一. 单项选择（共 15 小题；每小题 1 分，满分 15 分）

从A、B、C、D 四个选项中，选出可以填入空白处的最佳选项。

1. — Wasn't Joan supposed to be here by now? — __. She will be here in about twenty minutes.

2. Kate, __ sister I shared a room with when we were at college, has gone to work in Australia.

3. At first Robert wouldn't let his daughter go diving, but eventually he __ as she was so confident about her skills.

4. Let's not pick these peaches until this weekend __ they get sweet enough to be eaten.

5. — I'm moving in a few days and I wonder if you could help. — __. Just let me know when, and I'll be there.

6. The __ that there is life on other planets in the universe has always inspired scientists to explore the outer space.

7. I need a new passport so I will have to have my photograph __ .

8. It took him a long time to __ the skills he needed to become a good dancer.

9. The gold medal will be awarded to __ wins the first place in the bicycle race.

10. I can't find my purse. I __ it in the supermarket yesterday, but I'm not sure.

11. Bob thought he couldn't go to the party because he had to write a report, but he went __.

12. I didn't mean __ anything but the ice cream looked so good that I couldn't help __ it.

13. My washing machine __ this week, so I have to wash my clothes by hand.

14. It was only when the car pulled up in front of our house __ we saw Lily in the passenger seat.

15. If we __ the flight yesterday, we would be enjoying our holiday on the beach now.