She is often seen the old woman.A. helpB. helpingC. to helpD. help to

问题补充：

She is often seen the old woman.

A. help

B. helping

C. to help

D. help to

答案：

A. help

B. helping

(答案→)C. to help

D. help to

解析：根据题干的结构is seen可知，本句是被动语态，而see sb. do的被动语态是be seen to do。本句的意思是“她经常被看到帮助那个老妇人。”所以本题选C。