单项选择题
It is a fantastic landscape that we （）
A. never see B. did never see C. had never seen D. shall never see
单项选择题 —We didn't see him at the lecture yesterday.—He（）it.
单项选择题 He's working hard for fear that he（）
单项选择题 In architecture (建筑学), a vault (拱顶) is a proof or ceiling in the （） of an arch.
