More and more people have realized we won't have cleaner water to drink unless something ______ soon.[ ]

A. was done

B. will be done

C. to be done

D. is done

艉轴承密封装置油压试验是采用重力油柜润滑油，从泵油至回油连续（）min之内不准漏油。

A.6

B.5

C.4

D.3