Mother together with her children to the hospital.A. were sentB. are sentC. was sentD.

问题补充：

Mother, together with her children , to the hospital.

A. were sent

B. are sent

C. was sent

D. have been sent

答案：

A. were sent

B. are sent

(答案→)C. was sent

D. have been sent

解析：考查主谓一致：两个主语被together with连接，谓语动词要和前面的主语保持一致，这句话就和mother保持一致，句意：妈妈和孩子一起被送进医院。选C。