汉译英句型构建 — 英语选择题

请选择最恰当的选项补全译文：“应该鼓励大学生积极参加社会实践，这有助于他们了解社会并提高实践能力。” College students should 1______ actively take part in social practice, 2______ helps them understand society and improve practical skills. A. be encouraged to; which B. be encouraged to; that C. encourage to; which D. be encouraged; what