问题 选择题

海峡两岸直航后,原来从台北飞往上海要经过香港中转(以下称“A线路”),现在可以从台北直飞到上海(以下称“B线路”) .假设某人分别沿上述两条线路从台北到上海(如图),以下说法正确的是

A.沿A线路和B线路的路程相同,位移也相同

B.沿A线路和B线路的路程相同,位移不相同

C.沿A线路和B线路的路程不相同,位移相同

D.沿A线路和B线路的路程不相同,位移也不相同

答案

答案:C

题目分析:位移是由初位置指向末位置的有向线段,路程为路径的长度,故选C

点评:本题难度较小,理解位移与路程的概念和区别,本题从两概念的定义入手即可求解

阅读理解

阅读理解

       Hundreds of years ago, life was much harder than it is today. There was no modern medicine. 

       Life today has brought new problems. One of the biggest is pollution. Water pollution has made our

rivers and lakes dirty. It kills fish and pollutes our drinking water. Noise pollution makes us talk louder and become angry more easily. Air pollution is the most serious kind of pollution: It's bad to all living things in

the world.

       Cars, planes and factories all pollute our air every day. Sometimes the polluted air is so thick that it is

like a quilt over a city. This kind of quilt is called smog(烟雾).

       Many countries are making rules to fight pollution. Factories must now clean their water before it is

poured into rivers; they mustn't blow dirty smoke into the air.

       We need to do many other things. We can put waste things in the dustbin instead of throwing it on the ground. We can go to work by bus or with our friends in the same car. If there are fewer people driving,

there will be less pollution. Rules are not enough. Every person must help to fight pollution.

1. Hundreds of years ago, life was much harder than it is today because____.     

A. there were not any modern machines     

B. there was no pollution     

C. both A and B     

D. there were not many people   

2. What is the biggest problem in today's life?     

A. Water pollution.    

B. Air pollution.     

C. Noise.            

D. Pollution.  

3. The most serious kind of pollution is___       .   

A. noise pollution    

B. air pollution     

C. water pollution    

D. A, and C

4. Factories must clean their water____           

A. before they are poured into rivers     

B. when they are poured into rivers     

C. after it is poured into rivers     

D. before it is poured into rivers   

5. From the passage we know that________    

A. a few years ago, there was no smog at all     

B. today people don't have to talk to each other in a loud voice     

C. We can drink water from the polluted rivers and lakes     

D. people are making rules in order to fight pollution

名词解释