Mr. Liu for ten minutes.A. has leftB. will leaveC. has been awayD. left

问题补充：

Mr. Liu for ten minutes.

A. has left

B. will leave

C. has been away

D. left

答案：

A. has left

B. will leave

(答案→)C. has been away

D. left

解析：句意：刘先生已经走了10分钟了。根据for ten minutes要用现在完成时，而leave是瞬间动词，后面不能接一段时间；has been away离开，表状态，可以接一段时间，故选C。