题目

---Hi, Lucy．Have you heard of any good news about Frank recently?    ---Yeah．She ____ have done better．She has been admitted to one of the top-ten universities in the States．        A．shouldn’t            B．wouldn’t     C．needn’t      D．couldn’t 答案：D 解析: 略中，，BC＝3，则的周长为（    ） A． 　　　　　                         B． C．  　　　　　　                         D．