She closed her eyes. Thinking back through the years of being mo

She closed her eyes. Thinking back through the years of being mother, wife, friend, daughter, and sister.
【正确答案】：She closed her eyes, thinking back through the years of being a mother, a wife, a friend, a daughter, and a sister.
【题目解析】：题目中第二个句子不完整，没有主语和谓语动词，she与think之间是主动关系，故thinking back through...可做独立主格结构，表伴随。句意：她闭上眼睛，回想起做母亲、做妻子、做朋友、做女儿、做姐姐的那些年。