of course,it's good to do some practice tests but,

问题描述:

of course,it's good to do some practice tests but,
after a certain point,you don't learn anything new.after a certain

after在这句话可以理解为“当……的时候”,相当于when.
意思:当然了,做一些测试练习确实是好事,但是当你达到一定水准的时候,就很难再有进取了.
point可以理解为分数.