___,Mary had to stay at home to look after her.

问题描述:

___,Mary had to stay at home to look after her.
A.Her mother was ill B.Her mother being ill
注:要具体解析

B
A是一个完成的句子 后面的成分也是 两个完整的句子之间要用连词联起来 如果mary前面加个and就可以选A
B是一个独立结构 用了非谓语动词being,所以无需用连词