来回看了很多次35-45秒，动能和势能的转换。

来源: Sequoia_CA 于 2021-09-21 07:24:35 [博客] [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.