.

The growing speed of a plant is influenced by a number of conditions, _______are beyond our control.

A．most of them

B．most of which

C．most of what

D．most of that

在压力容器内检修时的行灯电压是（）伏。

A.规定6伏

B.规定12伏

C.规定24伏

D.规定48伏