A. has been known to scientists for years B. has only recently been discovered C. is known by everyone D. will probably remain a mystery 参考答案:B 答案解析:[听力原文]14-16 Why don't birds get lost on their long flights from one place to another Scienti
第30题: [单项选择]Questions 19~22A. Take a part-time job in England. B. Go to the States with the man. C. Discuss the plan with her parents. D. Ask her parents to pay for her trip home. 参考答案:D 答案解析:[解析] At the end of the conversation, what does the woman decide to do