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问题 选择题

函数f（x）=xcosx2在区间[0，4]上的零点个数为（　　）

A．4

B．5

C．6

D．7

答案

令f（x）=0，可得x=0或cosx2=0

∴x=0或x2=kπ+

π
2
，k∈Z

∵x∈[0，4]，则x2∈[0，16]，

∴k可取的值有0，1，2，3，4，

∴方程共有6个解

∴函数f（x）=xcosx2在区间[0，4]上的零点个数为6个

故选C

完形填空
完形填空。

Long long ago,there was a swan(天鹅)with golden feathers(金羽毛). She lived in a lake. A woman
lived in a small house 1 the lake with her two daughters. They were very poor. They worked hard all
yearround, 2  still, they lived a hard life and sometimes they even didn't have enough _3 to buy food.
    The swan was 4 to see that. She said to herself, "I'11 give one of my    5   to them each day , then
they can live a happy life with the money selling my feathers. "That evening , she 6   to the poor
woman's house and left a golden feather  on the table without saying 7 . From then on,the swan came
every day and gave them a feather. The woman was very happy because their life was much 8 than
before.But day after day, the woman became greedy(贪婪的). She said to her 9 ,"The swan may fly
away one day. If so , we will be poor again. We should take all 10 feathers when she comes next time. "
    "Oh no,Mom!"cried the daughters,"This will 11 the swan. She helps us a lot ! "But the mother wouldn't
listen. When the 12 came as usual, the mother caught her and took all her feathers. But suddenly, the
golden feathers 13 chicken feathers.
    Then , the golden swan said , "Poor mother , I came to 14   you, but you wanted to kill me.Now,
I am leaving and will    15    come back. Never be greedy! " With these words , the swan flew away.

( )1. A. above    
(     )2. A. and      
(     )3. A. money    
( )4. A. happy    
( )5. A. presents    
(     )6. A. flew      
(     )7. A  something  
( )8. A. duller    
(     )9. A. brothers    
(     )10. A. his      
(     )11. A. hurt    
(     )12. A. woman    
( )13. A. heard of    
(     )14. A. trouble    
(     )15. A. sometirries		B. over    
B. but    
B. time    
B. surprised
B. golden coins
B. ran    
B. everything  
B. better  
B. sisters  
B. her    
B. save    
B. daughter  
B. changed into
B. help    
B. always    		C. near  
C. so  
C. room  
C. sad  
C. feathers
C. climbed
C. nothing
C  busier
C. sons
C. their
C. protect
C. chicken
C. looked for
C. teach
C. usually 		D. under        
D. or          
D. energy      
D. scared      
D. collections  
D. walked      
D. anything    
D. harder      
D. daughters    
D. our          
D. refuse      
D. swan        
D. came from    
D. invite      
D. never        
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岳飞是著名的抗金英雄，却被 * * 臣秦桧等诬告而惨遭杀害。小明深有感触地说：“岳飞比窦娥还冤！”“窦娥”这一角色出自（    ）

A．唐诗

B．宋词

C．元曲

D．明清小说
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