These things are all (the things) ____they learn at school.

问题描述:

These things are all (the things) ____they learn at school.
用that 还是what 呢 答案只写了that 那为什么what 不可以呢

what 肯定不能用,因在在此处what=all that,或者你可以说These things are what they learn at school.