He ____ a machine the last time we saw him.A.was operating on B.w_英语解答

He ____ a machine the last time we saw him.
A.was operating on B.was operating
Why 这2个区别?

人气：286 ℃　时间：2019-12-26 06:17:41

解答

operate sth
操纵某物
operate on sth
给……做手术
这样明白了吧?怎么能给机器做手术呢?所以答案是B