题目

请你指出下列哪些是生物   （   ）A．钟乳石B．珊瑚C．珊瑚虫D．机器人 答案：C解析:略The kids from mountainous districts _________ never _________ computer games before.They' re so excited. A. have , played B. did , play　　 C. are , playing　　 D. do , play