起重机械中起着省力和支撑钢丝绳并为其导向作用的是( )。
A.卷筒B.滑轮C.吊钩D.制动器
参考答案:B
解析: 起重机械中起着省力和支撑钢丝绳并为其导向作用的是滑轮。
She was young _ so much money. [ ]
A. too; to give
B. to; to again
C. too; to given
D. too; to be given
眼球纤维膜由哪几个结构组成?