单项选择题
leaving the market place, the fat man looked pleased （） himself（）having discovered a bargain.
A. at, for B. at, at C. with, for D. with, at
单项选择题 During the Ice Ages, man developed the use of tools, and this is a way of protecting himself against（）
单项选择题 In architecture(建筑学) ,a vault(拱顶) is a proof or ceiling in the （） of an arch.
单项选择题 The doctor suggests that a person （） exercises every day if he wishes to be healthy.
