题目

8．在一次用餐中，同学们对燃料“固体酒精”产生了好奇．于是对其成分进行探究．【查阅资料】：（1）该固体酒精、氯化钙和氢氧化钠按一定的质量比混合制成的．（2）氯化钙、氯化钡溶液呈中性．【提出问题】：固体酒精中的氢氧化钠是否变质？【实验探究】：（1）取少量固体酒精于烧杯中，加足量的水充分溶解后静置，发现烧杯底部有白色沉淀，取沉淀于试管中加稀盐酸，有气泡产生，写出产生气体的化学方程式CaCO3+2HCl=CaCl2+H2O+CO2↑；分析Three Things to do Before You Are 18 Here are some things you should try before you are 18 for teenagers. (青少年) Learn to swim It is important for us, because it can save our lives. If you can’t swim well, you can’t do water sports like surfing and diving. Even taking a boat will be dangerous for you. Try at least one kind of team sports Being a good team player is an important skill. You can’t just think of yourself, but have to work well with other people. Other advantages (优点) of team sports like basketball ,football and baseball are that they keep you healthy, and they are also great fun. Teams usually have a good social life too—you’ll go to lots of parties and make many friends. Collect something One of the best hobbies for under-18s is collecting things. You could collect kinds of stamps, or you could collect other things, because that make you remember what you have done, like movie tickets （票）or e-mails from friends. The best way to collect is to have a special album（相册）to put your collection in and to write what each thing means（意思是） to you. 1.The most important reason for learning to swim is that ____ .A. it can save your life B. it can make you healthy C. you might easily do lots of things D. you can do sports water. 2.“A good social life” in the passage (短文)means ____ .A. you’ll study in groups B. you’ll go to parties and make many friends.C. you’ll take part in many parties. D. you’ll keep healthy.3.The writer tells us that one of the best hobbies is to ____ .A. collect something B. do some water sportsC. send e-mails to your friends D. have a special album4.The word “collect” may mean？A. 集邮 B.收集 C. 改正 D.数数5.The passage is mainly about ____ before you are 18.A. good habits to keep B. skills to have C. things to do D. collect many things