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，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
21.---You have been on tour for a week in our city during May Day. What do you think about it?
---Oh, what _______different Nanjing! It isn’t _______I saw last.
A./; the one      B. a; the one         C. a; one         D./; one