Question

【题目】It is important for us to work on the earth.

A.protectB.to protectC.protectingD.protected

Answer 1

【答案】C

【解析】

句意：对我们来说致力于保护地球很重要。

考查非谓语动词。A. protect保护，动词原形；B. to protect动词不定式；C. protecting动名词形式；D. protected动词的过去式。work on doing sth．意为"致力于做某事"。故选C。