I've been teaching long enough to know that doing derivations in class is equivalent to pouring ice water on the proceedings, so I do this sparingly.

我已经教了这么长时间书，所以我知道在课堂上讲推导，就好像泼冰水一样，所以我在讲这个的时候很小心。

youdao

I've been teaching long enough to know that doing derivations in class is equivalent to pouring ice water on the proceedings, so I do this sparingly.

我已经教了这么长时间书，所以我知道在课堂上讲推导，就好像泼冰水一样，所以我在讲这个的时候很小心。

youdao