美国是地多人少，可以广种薄收，中国不行，要提高单产，所以水利设施很重要。

来源: f2022f 于 2026-02-21 19:43:32 [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.