题目

Tom is the only one of the students who______ a winner of scholarship for four years. A. are        B. have been     C. has been       D. is 答案：C下列实验数据合理的是（　　）A．pH试纸测得某地雨水的pH为5B．托盘天平称得某纯碱样品的质量为10.57gC．10mL量筒量取6.53水mLD．20g食盐和l00g水配食盐水，溶质质量分数为20%