―Hurry,John!―Oh,damn!Bothmylegsarenearlytogiveout.I

问题详情：

―Hurry, John!

―Oh, damn! Both my legs are nearly to give out. I ________ for hours.

A. had walked                                    B. walked             

C. have been walking                         D. am walking

【回答】

知识点：现在完成进行时及其被动式

题型：选择题