单项选择题
A. at, for B. at, at C. with, for D. with, at
During the Ice Ages, man developed the use of tools, an...
单项选择题During the Ice Ages, man developed the use of tools, and this is a way of protecting himself against（）
A. conflicts B. hazards C. faults D. shortcomings
In architecture(建筑学) ,a vault(拱顶) is a proof or ceiling...
单项选择题In architecture(建筑学) ,a vault(拱顶) is a proof or ceiling in the （） of an arch.
A. form B. figure C. shape D. appearance
The doctor suggests that a person （） exercises every da...
单项选择题The doctor suggests that a person （） exercises every day if he wishes to be healthy.
A. does B. did C. do D. will do
