His family at home.A. is allB. all isC. are allD. all are

问题补充：

His family at home.

A. is all

B. all is

C. are all

D. all are

答案：

A. is all

B. all is

(答案→)C. are all

D. all are

解析：句意:他的家人都在家。这句话的主语是his family,他的家人，强调个体，表示复数的概念，做主语时，谓语动词用复数；如果强调一个整体的时候，则视为单数，谓语动词也用单数。all 应放在be 动词之后，实意动词之前。故选C。