Question

---Has Tom finished his task yet?
---I’m not sure. But he ______ on it last week.

1. A.
   was working
2. B.
   has been working
3. C.
   worked
4. D.
   had been working

Answer 1

A
试题分析：考查时态。句意：——Tom完成了他的任务吗？——我不确定。但是他上周一直致力于这个任务。根据语境，说明与过去有关，且表示过去一段时间（last week）内一直在做某事，故使用过去进行时。
考点：考查时态。