这些不是科学范畴之内。四大发明是工程学。

来源: 笑薇. 于 2019-03-31 06:56:30 [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