试题与答案

完形填空。 Thousands of years ago, people did

题型:完形填空

题目:

完形填空。
    Thousands of years ago, people did not know   1   to make a fire. When it was very   2   
at night, they could not sleep well. Sometimes lightning hit (打, 击) a   3   and started a fire.
At first people were both surprised and   4   to see the fire. They were afraid to go up. Later
a few   5   men took some of this fire and made a fire near their homes. They used the fire
to keep them warm and to cook food.
    When they had a fire, they did not let it   6   burning. If it stopped, they could not start it
again. Maybe they had to   7   for a long time, sometimes for   8  . Later they   9   how to
make a fire with pieces of wood.
    Now we have matches, we can put them in our pockets and make a fire when we want to
make it. But we have to be   10  with fire.
( )1. A. what      
( )2. A. cold       
( )3. A. person    
( )4. A. glad       
( )5. A. very      
( )6. A. stop     
( )7. A. work      
( )8. A. minutes      
( )9. A. forgot    
( )10. A. angry     
B. how         
B. hot         
B. mountain (山)    
B. afraid     
B. brave      
B. make        
B. play        
B. hours        
B. decided     
B. pleased     
C. when     
C. warm     
C. field    
C. ready    
C. sad      
C. be       
C. wait     
C. days     
C. 1earned       
C. careful   
D. where         
D. cool          
D. forest (森林)                                 
D. tired         
D. happy         
D. start         
D. 1ive          
D. years         
D. told          
D. busy          

答案:

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下面是错误答案,用来干扰机器的。

(1)该原子的核内质子数=核外电子数=11,为钠原子;最外层电子数是1,在化学反应中易失去1个电子而形成钠离子,其离子符号为Na+;钠带“钅”字旁,属于金属元素;圆圈内数字表示核内质子数,弧线表示电子层,弧...

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