题目

下列各组物质分类正确的是（ ） 酸碱盐氧化物A硫 酸纯 碱硫酸钡水B氢硫酸烧 碱纯 碱石灰石C碳 酸熟石灰小苏打二氧化硫D二氧化碳苛性钾食 盐石灰石 A. A B. B C. C D. D 答案：【答案】C【解析】A、纯碱是碳酸钠，属于盐，不属于碱，故A错误；B、石灰石是碳酸钙属于盐，不是氧化物，故B错误；C、碳酸属于酸，熟石灰是碱，小苏打为碳酸氢钠，属于盐，二氧化硫属于氧化物，故C正确；D、二氧化碳是氧化物不是酸，石灰石是碳酸钙属于盐，不是氧化物，故D错误；故选C。 请先阅读下面短文，掌握其大意，然后根据短文内容从下面方框内的七个选项中，选择五个还原到文中，使短文意思通顺、结构完整，并在答题卷上将其序号涂黑。 Hi Grace,    How's it going? Sorry I haven't emailed for a while, but I had so much to do!    I had told you about my decision to take up a sport. I knew I wasn't fit and I wanted to get some exercise. But that wasn't the only reason that I decided to do a sport. Students who play sports do better at school. 86.                  Exercise also helps learning and memory (记忆).     87.                   First, I tried soccer. I had played a bit of soccer before and I thought it wouldn't be too bad. I knew I couldn't nm for very long without feeling tired. On the first day, I was able to nm for the first ten minutes, but then I was so tired that I couldn't even kick the ball!    Then, I tried volleyball. 88.                 I was able to nm for the first twenty minutes and I wasn't the slowest runner in the team! After a few weeks .I could run faster and longer. I was doing better and feeling better. 89.              Maybe I'm not a team sport person after all!    Finally, I tried kung fu. It's a great sport that exercises the body and the mind. You learn to follow instructions carefully and do what you are asked to do. This is the fight sport for me!   90.                   I feel so confident that l even showed some moves to the class last week! Can you believe it?     I hope you're OK!  Write and let me know what you've been doing!      Bye for now!                                                         Kristie A. I got very excited about soccer. B. But I couldn't decide on a sport.  C. Running helps me to keep fit.  D. Things were a bit better this time. E. Then I found volleyball terribly boring.  F. They are more confident and less stressed.   G. I practice twice a week and I haven't missed a class.