（1）2008年奥运会“祥云”火炬中燃料燃烧后不会对环境造成污染，体现了“绿色奥运”的理念．反应的化学方程式为CxH8+5O2
yCO2+4H2O，则x的数字是______． 点燃 .
（2）汽车尾气（含有CO、SO2和NO等物质）是城市的污染物，治理的方法之一是在汽车的排气管上安装催化转换器，其特点是使CO和NO在催化剂的条件下反应生成可参与大气生态循环的无毒气体氮气和二氧化碳．写出CO和NO反应的化学方程式______．
（1）根据质量守恒定律，化学反应前后原子的个数不发生改变，根据氧原子可得10=2y+4，解得y=3．反应后C原子的总数为3，所以反应前C原子的总数也得为3，所以x=3；
（2）CO与NO反应，生成可参与大气生态环境循环的无毒气体，即生成CO2和N2，其化学方程式为2CO+2NO
N2+2CO2． 催化剂 .
故答案为：3；2CO+2NO
N2+2CO2． 催化剂 .
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| You Can't Be Replaced As a teenager, I felt I was always letting people down. I was rebellious (叛逆的) on the outside, 1 on the inside I wanted people to 2 me. Once I left home to hitchhike (搭便车) to California with my friend Penelope. The trip wasn't 3 and there were many times I didn't feel safe. One situation in particular left me 4 for still being alive. When I returned home, I was different -not so outwardly (外表上) sure of myself. I was happy to be home. But then I noticed that Penelope, who was 5 with us, was wearing my clothes. And my 6 seemed to like her better than me. I wondered if I would be 7 if I weren't there. I told my mom, and she explained that 8 Penelope was a lovely girl, no one could 9 me. I pointed out, "She is more patient and is neater than I have ever been." My mom said these were wonderful 10 but I was the only person who could fill my 11 . She made me realize that even with my 12 , -and they were many-I was a loved member of the family who couldn't be replaced. I became a searcher, 13 who I was and what made me unique. My 14 of myself was changing. I wanted a solid base to start from. I started to resist pressure to 15 in ways that I didn't like any more, and I 16 who I really was. I came to feel much more 17 that no one can ever take my place. Each of us holds a unique place in the world. You are 18 no matter what others say or what you may think. So 19 about being replaced. You 20 be. | ||||
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