第一节：语法和词汇知识（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。
单选题
21. By nature, you are an adventurer, full of amazement and curiosity about
world bigger than life itself.
A. a; the B. the; the C. /; a D. the; /
22. --- Be careful! Don’t forget you are on a ladder.
--- But you are holding it for me, nothing _________.
A. to worry about B worry about. C. is worried about D. worrying about
