我觉得是对的，上山每步短,下山每步长. Stride length is different.

来源: 孔方兄94 于 2018-01-28 06:55:53 [旧帖] [给我悄悄话] 本文已被阅读：次

WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.