Question

I know_____ it’s you rather than anyone else that are to blame for the mistake.

I know_____ it’s you rather than anyone else that are to blame for the mistake.
A. for sure B. to be sure C. for the sure D. for a sure
请说明理由

Answer 1

A. for sure是型握固定用卜逗庆法，意为肯定、确切。
我确信是你而不是别指梁人应当为那个错误负责。

追问

B为什么不行？

追答

to be sure是用来作状语的，一般要有逗号隔开，意思是固然、当然。在这里，语气和意思都不相合。