Question

【題目】At present there are more and more private cars. They have caused serious air________ (pollute).

Answer 1

【答案】pollution

【解析】

句意：目前有越來(lái)越多的私家車。它們?cè)斐闪藝?yán)重的空氣污染。

pollute動(dòng)詞，污染。結(jié)合句意和空前air可知這里用短語(yǔ)“空氣污染”air pollution，所以這里用pollute的名詞形式pollution，故填pollution。