问题 探究题

如图甲所示是小红同学测定电阻的实物连接图

(1)电源电压6V,请用笔画线代替导线,帮她完成电路的连接.(要求滑动变阻器滑片向右移动时电阻变大);

(2)电路连接无误后,闭合开关,电流表指针不发生偏转,电压表指针有偏转,请帮她找出故障的原因(填下列故障原因的代号)_________

A、小灯泡短路          

B、电源接触不良

C、小灯泡断路          

D、电流表内部短路

(3)排除故障后闭合开关,电流表和电压表的示数如图乙所示,电压表的示数为_________V,电流表的示数为_________A,小灯泡的电阻为_________Ω.

答案

(1)如图:

(2)C;

(3)1;0.3;3.

完形填空
完形填空。
    Some people think that all wild animals are dangerous. But in fact, very few of them will    1   a man if he
leaves them alone. If you meet a lion or an elephant, I guess you will   2  ; but even a lion will avoid (躲避) a
man if it is not very   3  . Lions and tigers only kill and eat men when they have grown too old and too weak
to catch their usual   4 , such as deer and   5  small animals. If you see a wild elephant, perhaps you will be 
  6  . However, elephants usually run away at once if you don't attack them. Some animals get very
frightened if they only smell a man, some stand and look at him for a moment   7   they run away, some take
no notice at all but walk away   8   in another direction. Wild animals only attack   9   when they are afraid that
people want to harm their   10 , or when the hunters shoot at them and make them angry.
( )1. A. bite    
(     )2. A. come nearer
(     )3. A. thirsty   
(     )4. A. food    
(     )5. A. others   
(     )6. A. excited   
(     )7. A. before   
(     )8. A. luckily   
(     )9. A. dogs    
(     )10. A. neighbours 
B. attack   
B. break down   
B. excited  
B. fish    
B. other  
B. pleased 
B. after   
B. noisily  
B. people   
B. friends  
C. protect    
C. stay alive    
C. tired     
C. things     
C. another    
C. frightened   
C. as soon as   
C. quietly    
C. children    
C. young babies   
D. hide    
D. run away                         
D. hungry  
D. drinks  
D. any     
D. angry   
D. while   
D. loudly  
D. other   
D. parents 
单项选择题