问题 填空题

有如下三个反应表达式:

①CaCO3

 高温 
.
 
CaO+CO2

②H2CO3

  △  
.
 
H2O+CO2

③CaCO3+2HCl═CaCl2+H2O+CO2

请通过分析叙述三个反应的共同点是______,其中有一个与另外两个反应不同,请指出其中一个与另外两个反应的不同点是:______.

答案

三个反应的共同点是生成物中都含有二氧化碳.故填:生成物中都含有二氧化碳.

其中一个与另外两个反应的不同点是:③属于复分解反应,①②属于分解反应.

故填:③属于复分解反应,①②属于分解反应.

阅读理解

阅读理解。

        Maybe ten-year-old Elizabeth put it best when she said to her father." But, Dad, you can't be healthy if you're dead."

      Dad in a hurry to get home before dark so he could go for a run, had forgotten to wear his safety

belt-a mistake 75% of the US population make every day. The big question is why.

      There have been many myths about safety belts ever since heir first appearance in cars some forty

years ago. The following are three of the most common.

      Myth Number One: It's best to be "thrown clear" of a serious accident.

      Truth: Sorry, but any accident serious enough to "throw you clear" is also going to be serious enough

to give you a very bad landing. And chances are you'll have traveled through a windshield (挡风玻璃)

or door to do it. Studies show that chances of dying after a car accident are twenty-five times greater in

cases where people are "thrown clear."

      Myth Number Two: Safety belts "trap" people in cars that are burning or sinking in water.

      Truth: Sorry again. but studies show that people knocked unconscious (昏迷) due to not wearing

safety belts have a greater chance of dying in these accidents People wearing safety belts are usually

protected to the point of having a clear head to free themselves from such dangerous situations, not to be

trapped in them.

      Myth Number Three: Safety belts aren't needed at speeds of less than 30 miles per hour.

      Truth: when two cars traveling at 30 m/ph hit each other, an unbelted driver would meet the

windshield with a force equal to diving headfirst into the ground from a height of 10 meters.

1. Why did Elizabeth say to her father, "But, Dad, you can't be healthy if you're dead"?

A. He was driving at great speed.

B. He didn't have his safety belt on.

C. He was running across the street.

D. He didn't take his medicine on time.

2. The reason Father was in a hurry to get home was that he _____.

A. wasn't feeling very well        

B. hated to drive in the dark

C. wanted to take some exercise    

D. didn't want to be caught by the police

3. According to the text, to be "thrown clear" of a serious accident is very dangerous because you ____.

A. may get seriously hurt being thrown out of the car

B. may be knocked down by other cars            

C. may find it impossible to get away from the seat  

D. may get caught in the car door

4. What is the advice given in the text?

A. Never drive faster than 30 mile an hour.      

B. Never forget to wear the safety belt while driving.

C. Try your best to save yourself in a car accident.

D. Drive slowly while you're not wearing a safety belt.

单项选择题