Question

15. Everyone in this country should work hard and do what they can    against national smog.

A. fight      B. fought

C. fighting    D. to fight

Answer 1

15.   D考查非謂語(yǔ)動(dòng)詞。句意：這個(gè)國(guó)家的每一個(gè)人都應(yīng)該努力去盡他們自己所能去抵抗全,性的霧霾。分析句子結(jié)構(gòu)可知what they can是作動(dòng)詞do的賓語(yǔ)，can后省略了實(shí)義動(dòng)詞do,后面是不定式作目的狀語(yǔ)。故選D。