题目

下列鉴别物质所用的方法或试剂，错误的是 A. 氧气和氮气——观察颜色                    B. 铁粉和炭粉——用稀硫酸 C. 羊毛和化学纤维一-点燃闻气味           D. 氢氧化钠溶液和水——用酚酞溶液 答案：A Mr Paul often spoke to us and         carefully.we loved him very much... A. was always listened                  B. was always listened to          C. always was listened to               D. always listened to