第二部分：英语知识运用（共两节，满分45分）
第一节：单项填空（共15小题；每小题1分，满分15分）
从A、B、C、D四个选项中，选出可以填人空白处的最佳选项，并在答题卡上将该项涂黑。
21. Not until the train pulled into the next station____ that the suitcase was gone.
A. did he find B. had he found C. he had found D. he found
22. ----Just a moment. I haven’t finished packing my suitcase.
----________. It’s high time we left for the airport.
A. Go ahead B. Take it easy C. Hurry up D. That’s fine
23. Unless_____ to speak, you should remain silent at the conference.
A. invited B. inviting C. being invited D. having invited
24. Just in front of the temple ________ with a history of 1,000 years.
A. does an old pine tree stand B. stands an old pine tree
