i very sorry, ____i had to help my mother because she was ill.A:but B:orC:andD:so选什么,求解 在线等.要解释

问题描述:

i very sorry, ____i had to help my mother because she was ill.
A:but
B:or
C:and
D:so
选什么,求解 在线等.要解释

选A,这个在英语中就是要转折的,没有道理说的

A
这是惯用方法,记住就行了,没什么说法.