题目

—Are you going to take part in the speech competition? —       . It’s too good a chance to miss. A. NO problem       B. Thanks a lot     C. Never mind           D. That’s for sure 答案：D现实生活中常用氯气给自来水消毒，某学生用新接自来水配制下列物质的溶液，不会产生明显变质的是（）。A.石蕊                                   B.硝酸银C.亚硫酸钠                             D.氯化铝