___that is important is that doing your best.A.All B.Everything答案是A,我想问为什么不选B?

问题描述:

___that is important is that doing your best.A.All B.Everything答案是A,我想问为什么不选B?

All that=what
好像有这么个用法.all这里起的是代词作用.
B不能在that前面.去掉that好像就可以选了.