题目

The railway Qinghai to Tibet is the longest plateau (高原) railway in the world.          A. connected            B. connects              C. connecting        D. is connected 答案：C5．鲫鱼的身体为梭形，其主要作用是为了（　　）A．逃避敌害B．减轻体重C．减少阻力D．协助身体运动