A、Her illness. B、The Civil War. C、Her trip to England. D、Her grandmother’s death. B推断题。文章结尾处提到，南北战争期间(the Civil War)，Dorothea在联盟

Dorothea Dix left home at an early age — of her own free will — to live with her grandmother.
    At fourteen, Dorothea Dix was teaching school at Worcester, Massachusetts. A short time after she had begun teaching, she established a school for young girls in her grandparents’ home. Stress was placed on moral character at Dorothea Dix’s school, which she conducted until she was thirty-three.
    She was forced to give up teaching in her grandparents’ home, however, when she became ill. A few years of inactivity followed. In 1841 Dorothea Dix began to teach again, accepting a Sunday school class in the East Cambridge, Massachusetts’ jail. Here, she first came upon insane people locked up together with criminals.
    In those days, insane people were treated even worse than criminals. There were only a few asylums in the entire country. Therefore, jails, poor houses and houses of correction were used to confine the insane.
    Dorothea Dix made a careful investigation of the inhuman treatment of the insane. It was considered unfeminine for a woman to devote herself to such work at this time. But this did not stop Dorothea Dix in her efforts to provide proper medical care for the insane.
    Gradually, because of her investigations, conditions were improved. More than thirty mental institutions were founded or reestablished in the United States because of her efforts. Dorothea also extended her investigations to England and to other parts of Europe.
    During the Civil War, Dorothea served as superintendent of women hospital nurses in the Union Army. When the war was over, she returned to her work of improving conditions for insane people.
29. How did Dorothea Dix first become aware of the mistreatment of insane people?
30. Which of the following statements about Dorothea Dix is true, according to the passage?
31. What interrupted Dorothea Dix’s work with the insane?