Don't be too hard on him．After all,it was for the first time ( ) he made such a mistake．
问题描述：
Don't be too hard on him．After all,it was for the first time ( ) he made such a mistake．
A．that B．when C．since D．before
这考的是什么从句,答案为什么是A B为什么不行?
答
我想问,其实你系唔系打错左啊,应该无for呢个单词吧?