Question

【题目】—Where is he exactly?

—I don’t know, but I saw him _______ an experiment in the lab when I passed by.

A. to conduct B. conducted

C. conducting D. conduct

Answer 1

【答案】C

【解析】

试题分析：考查动词非谓语形式。句意：——他到底在哪里？ ——我不知道，但是当我路过的时候，我看见他正在实验室做实验。根据语境，本句为see somebody doing something，故选C。