题目

下列常见的数据正确的是： A．中学生的身高约为170cm                                B．夏天教室的温度约为50℃ C．成年人步行的速度约为3m/s                           D．人正常心跳两次间隔时间大约是1min 答案：A A person _____a foreign language most be able to use the language ______all his own. A．learning ,forgetting B．to learn, to forget C．using ,but D．who learns ,to forget