---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
网友回答
A. had walked
B. walked
(答案→)C. have been walking
D. am walking
解析：考察时态。根据for hours和my legs are nearly to give out可知我已经连续步行好几个小时了，故使用现在完成进行时，故C正确。句意“我的双腿几乎走不动了，我已经连续步行好几个小时了。