his mother has to take care of him at home.A. Being illB. He being illC. He is illD. His

问题补充：

, his mother has to take care of him at home.

A. Being ill

B. He being ill

C. He is ill

D. His to be ill

答案：

A. Being ill

(答案→)B. He being ill

C. He is ill

D. His to be ill

解析：考查独立主格结构。独立主格结构不是句子，是一个短语，但是作用相当于句子。当分词做状语的时候，如果分词的逻辑主语与句子主语没有关系，就在分词的前面直接加上逻辑主语，形成独立主格结构，该结构在作用上久相当于一个状语从句。本句在两个部分之间没有连词，说明前面一部分是独立主格结构，He being ill=Because he is ill.句意：因为他病了，他的妈妈不得不在家照顾他。故B正确。