第二节 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。
6. ---May I put my luggage on the seat beside you, sir, if it is free?
---____.
A. Sure, with pleasure B. Oh, please yourself
C. Well, never mind D. Yes, help yourself
7. This kind of work ____ care and patience.
A. calls up B. calls on C. calls for D. calls at
