Question

【题目】

The scientist, who space all his life, is retiring next week.

A. had explored

B. is exploring

C. has been exploring

D. explored

Answer 1

【答案】C

【解析】现在完成进行时表示一直做某事，动作或状态从过去开始持续到现在，还在进行中，也很可能持续下去。