第20题: [简答题]Throughout the night a person usually dreams for about one and a half hours. Many people say that they don’t dream, or that they rarely dream. Doctors have studied the sleep and have found that everyone dreams — in fact, every person needs to dream in order to keep healthy. 参考答案:一个人一夜通常有一个半小时在做梦。很多人说他们没有做梦，或者是很少做梦。医生们研究了睡眠，发现每个人都要做梦，事实上，每个人都需要做梦来保持身体健康。 答案解析:Throughout意为“贯穿，遍及”，in fact为“实际上，事实上”，in order to keep healthy为不定式表示目的状语。
