题目

 既可以用来鉴别乙烷与乙烯，又可以用来除去乙烷中的乙烯以得到纯净乙烷的方法是（ ） A. 通过足量的NaOH溶液    B. 通过足量的溴水 C. 在Ni催化、加热条件下通入H2    D. 通过足量的酸性KMnO4溶液 答案：【答案】B 【解析】A．乙烷与乙烯通过足量的NaOH溶液，不发生反应，不能提纯物质，故A错误；B．乙烷性质稳定，与溴水不反应，乙烯含有C=C官能团，能与溴水发生加成反应生成二溴乙烷而使溴水褪色，故B正确；C．通入氢气不能鉴别乙烷和乙烯，且能引入新的杂质，故C错误；D．通过高锰酸钾溶液，乙阅读下面短文，用括号内所给动词的适当形式填空（必要时可加情态动词或助动词）。A little girl lives at the far end of Islington Road in Newton, Massachusetts. All the neighbors 1. (like) this pretty and lovely girl. Unfortunately, two-year-old Samantha is deaf."She wants 2. (talk) with someone," said her father, Raphael. "She will feel excited when it's someone who can 3. (communicate) with her," said her mother, Glenda.Her excitement for communicating with others is painfully obvious (明显的) to everyone in the neighborhood. Whenever they saw her on a walk or in her yard-and Samantha 4. (try) talking with them-they found themselves at loss for understanding her words.On their own, Sam's neighbors got together and found a sign language teacher. Now her neighbors 5.(take) sign language class. Everyone looks so careful. Rhys, the teacher, says this is wonderful because a lot of time even the parents of deaf children don't bother (费心) to spend time 6. (learn) sign language."But here Sam has a full community that's willing to communicate with her, and it is a beautiful story," Rhys says. And he says this certainly 7. (make) a happier Samantha.Her parents say there aren't words in any language to express their thanks. "It's really touching and we are so fortunate," her parents say. In fact, they say they 8. (see) their daughter who is so happy for a long time.They 9. (work) hard at an American Sign Language class when Samantha went into class. "The first word she said to us was 'friend'," said one neighbor, "I 10. (move) and I thought your heart would melt (融化) just as mine did." What makes a "good neighborhood" is nothing more than good neighbors.