题目

下列变化属于化学变化的是（ ）A. 海水晒盐B. 活性炭吸附冰箱内的异味C. 燃放烟花D. 分离液态空气制氧气 答案：【答案】C【解析】物理变化和化学变化的根本区别在于是否有新物质生成，如果有新物质生成，则属于化学变化； 反之，则是物理变化。燃放烟花，有新的物质生成，是化学变化，海水晒盐 、活性炭吸附冰箱内的异味、 分离液态空气制氧气都只是将混在一起的物质分离，没有新的物质生成，是物理变At Life’s CrossroadsLeaving high school, I had to choose a career path—medicine or business—before college started in three months, but I couldn’t decide. Both my uncles suggested I work for a month in a         followed by a month in a hospital before I could know what to do. It seemed like a good idea.Then near the end of two months, I began thinking about my two         . The bank had offered better working conditions. The hospital was full of excitement, but the training was hard. It seemed that the choices of        was going to run out.The Last day of my work at the hospital, I was         home when I saw a boy hit by a bus and lie in the road as the bus run away.        stopped. I know if the boy stayed there, he would die very soon. So, without help, I lifted him into my car.The next day, I went to see him. His family were sitting around his bed. The doctor introduced me as “the person who saved the boy’s life”.Everyone got up, with        smiles on their faces. The mother held my hands to her face, repeating again and again, “See, you are an angel!”What a feeling this was, to help save the life of another person!         , I knew I wanted to do for the rest of my life. I went to college for my medical studies.We may spend a lot of time wondering about what         to take in our lives, but sometimes you don’t really have to worry about your       decisions. They are made for you by some quality(品质) in you—by what you’re        to do when necessary.小题1:A．teamB．companyC．gardenD．laboratory小题2:A．unclesB．hobbiesC．colleges D．experiences小题3:A．businessB．educationC．careerD．subject小题4:A．runningB．ridingC．stayingD．driving小题5:A．All B．FewC．NobodyD．Someone小题6:A．gentleB．weak C．pleasant D．grateful小题7:A．LuckilyB．ProbablyC．ImmediatelyD．Quietly小题8:A．pathB．actionC．interest D．advice小题9:A．big B．personalC．quickD．fair小题10:A．freeB．afraidC．readyD．careful