I hope that the little ________ I have been able to do does good to them all.

A．which

B．what

C．that

D．when

选矿厂选用的浮选工艺流程的复杂程度，具有（）等特点

A.与矿物的物理性质无关

B.与选前准备工作程度无关

C.与选矿厂技术条件有关

D.与所建尾矿库大小有关