19和20是含糊一点。9和20就量变导致质变了。

来源: 大号蚂蚁于 2018-05-21 08:03:16 [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.

Change Ad Consent