单项选择题活塞发动机的总工作容积越大,说明A. 进气量越大,功率越大B. 进气量越大,混合气越贫油C. 进气量越大,喷油多,发动机经济性越差D. 进气量越大,混合气越富油
单项选择题Can you tell the main reason why the Chinese build towers besides beautification of the city? A. for playing game. B. for setting fireworks.C. for military defense. D. for traffic flow.