从A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
11. ____ 202 km Shanghai-Hangzhou high-speed railway, with ____ design speed of 350 km per hour, began its operation on Oct 26, 2010.
A. The; a B. The; the C. A; a D. A; the
12. ---- Her father is very rich．
---- ____ She wouldn’t accept his help even if it were offered．
A. What for? B. So what? C. No doubt. D. No wonder.
13. Before the College Entrance Examination, some students have shown ____ of tension. Some have trouble in sleeping while others have lost their appetite.
