题目

 ---Look, he is too tired.          ---Yes, why not ask him______ a rest.         A.stop having          B. stop to have            C. to stop to have   D.to stop having 答案：C18．下列动物中过着寄生生活的是（　　）①血吸虫 ②绦虫 ③华枝睾吸虫 ④珊瑚虫．A．①②③B．①②④C．②③④D．①②③④