问题 填空题

(1)夏天不少人喜欢点蚊香驱蚊.据媒体报道:蚊香中有些成分不完全燃烧会产生致癌物质.甲醛(CH2O)是蚊香的成分之一,请回答:甲醛由______元素组成,该物质中碳元素与氢元素的质量比为______.

(2)2008年5月12日14时28分,四川汶川发生里氏8.0级强烈地震,造成大量人员伤亡.为了确保大灾过后无大疫,灾区急需大量的各种消毒防疫物质,漂白粉[主要成分是Ca(ClO22和CaCl2]就是其中一种.工业上是用氯气(Cl2)和石灰乳[Ca(OH)2]为原料生产漂白粉,其原理是氯气与石灰乳反应生成次氯酸钙[Ca(ClO)2]、氯化钙

和水.请写出该反应的化学方程式:______.

答案

(1)甲醛是由碳、氢、氧三种元素组成的;该物质中碳元素与氢元素的质量比为(12×1):(1×2)=6:1.

(2)氯气与石灰乳反应生成次氯酸钙[Ca(ClO)2]、氯化钙和水,该反应的化学方程式为:2Ca(OH)2+2Cl2=CaCl2+Ca(ClO)2+2H2O.

故答案为:(1)3种;6:1;(2)2Ca(OH)2+2Cl2=CaCl2+Ca(ClO)2+2H2O.

阅读理解

IV. 阅读理解:(第一节15小题,每小题2分;第二节5小题,每小题2分;满分40分)               

Stress ---- learning to relax

During the course of our growing, sometimes everything seems to go wrong at once. Maybe you have got behind with school work, quarreled with a friend, lost something you really liked and you're in trouble at home too. As more things happen we get more stressed, which means we get too tired and can't think properly, which means more things go wrong!

What happens when you feel stressed?

When you get worried or stressed out about something it affects your body in a number of ways.

○ Your heart beats faster. 

○ Muscles tense.

○ Your stomach feels tight or you feel sick.

○ Your breathing gets faster.

○ You sweat more.

○ It is hard to get to sleep, or you wake up feeling like you didn't really sleep because you still feel tired. 

What can you do if you feel stressed?----Relaxation

There are different things you can do to relax.

Exercise is great and it can help you sleep if you are doing some as part of your day. If you're not sure what to do, look up 'Exercise' on this site for some ideas.

Exercise to move about (dancing, running, jumping, walking and bike riding) is very good, but if you are not an active person then here are some ideas for you.

Exercise to do if you are a couch potato(电视迷) or a computer freak(电脑迷) or a bookworm .

While you are sitting you can still exercise.

Look at the diagrams.

61. What will happen when things go wrong?

A. Falling behind in study.                   B. Making friends with others.

C. Picking up some money                    D. Feeling well

62. Where can we find this passage?

A. In a newspaper.                     B. In a magazine.

C. In a textbook.                   D. At a website.

63. The underlined word “bookworm” in the third line from the bottom probably means_______.

A. an insect that eats books                   B. someone who likes reading very much

C. a worm that likes books                    D. a person who often does sports outside

单项选择题