写出下列各句中against的含义。
① He is standing against the wall. ______
② Your parents are against your plan to travel alone. ______
③ We should build a wall against the floods (洪水). ______
④ They are playing against each other in the tennis match. ______

① 倚着；紧靠 ② 反对 ③ 防御 ④ (与对手)对阵；对抗

① 这所学校有三千名学生。
There are ______ ______ students in this school.
② 图书馆里有成千上万本书。
There are ______ ______ books in the library.

① three thousand ② thousands of

① 桌上的便条提醒我今天有音乐会。
The note on the table ______ ______ ______ the concert today.
② 他的话提醒我应该先完成我的家庭作业。
His words ______ ______ that I should finish my homework first.

① reminded me of ② reminded me