----There can be no life on the earth without water.--That’s right. Water everywhere.A

问题补充：

----There can be no life on the earth without water.

----That’s right. Water everywhere.

A. needs

B. is needing

C. is needed

D. needed

答案：

A. needs

B. is needing

(答案→)C. is needed

D. needed

解析：句意：没有水，地球上就不会有生命。——是的，到处都需要水。结合语境可知下文描述的是客观性的动作，故用一般现在时态。主语是动作对象，故用被动语态，选C。