It is immediately obvious that water is to be _______ to the development of life.

A．compulsory

B．controversial

C．fundamental

D．supreme

车轮上标记可采用（）等方式生成。

A.热压、冷打和铸造

B.热压、冷打、锻造

C.热压、铸造、锻造

D.冷打、锻造、铸造