Why don’t和Why not有啥区别?

问题描述:

Why don’t和Why not有啥区别?
( ) 2.--- Our teacher wouldn’t give us the answers ___ the question directly.
  --- _____ work them out by ourselves?
  A.of,Why not B.to,Why don’t
  C.of,What about D.to,Why not
以此为例!

选D
"the answer to the question"是固定搭配 ".的答案"
"Why don't"之后要接主语人比如you,we,she,he,they等.
"Why not"之后接动词原形
而“work"是动词原形
所以选D