Animals suffered at the hands of Man _______they were destroyed by people to make way

for agricultural land to provide food for more people.[ ]

A．in which    

B．for which    

C．so that    

D．in that

当主要尺寸和转舵扭矩相同时，（）转舵机构的工作油压最高。

A.拨叉式

B.滚轮式

C.转叶式

D.十字头式