第12题: [单项选择]The reason why birds don't get lost on long flights ______. A. have been known to scientists for many years B. have only recently been discovered C. are known by us D. will probably remain a mystery 参考答案:B 答案解析:见第一段中句子“Scientists have puzzled over this question for many years.Now they're beginning to fill in t
第26题: [简答题]But is it interfering with personal freedom to insist that they go to live with some of their relatives so that they might be taken better care of (Passage 2) 参考答案: 答案解析:为了让老人得到更好的照顾,我们让他们与自己的某些亲戚住在一起,但这是不是干涉了人家的个人自由了呢