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问题 解答题
已知直线l的参数方程为
x=
3
+
1
2
t
y=2+
3
2
t
（t为参数），曲线C的参数方程为
x=4cosθ
y=4sinθ
（θ为参数）．
（1）将曲线C的参数方程化为普通方程；
（2）若直线l与曲线C交于A、B两点，求线段AB的长．
答案

（1）将等式两边同时平方      x2=16cos2θ，y2=16sin2θ

       然后相加即可求出曲线C的参数方程化成普通方程x2+y2=16

（2）将

x=
3
+
1
2
t
y=2+
3
2
t
代入方程x2+y2=16，并整理得t2+3
3
t-9=0

设A、B对应的参数为t1，t2，则t1+t2=-3

3
，t1t2=-9，

|AB|=|t1-t2|=3

7

单项选择题

无论是向左或向右转舵，浮动杆追随机构的储存弹簧（）。

A．始终受压

B．始终受拉

C．偏转舵时受压，回舵时受拉

D．偏转舵时受拉，回舵时受压
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完形填空
完形填空。

     Having left the town, the girl stopped the car at the landing near the entrance of the bay (海湾). She
stepped into the   1   and rowed out silently. The tide was rushing to the entrance and   2   to the wild open
sea. She had to row across the bay to reach   3   side. The waves struck against the side of the boat,   4   
and uneven ; it became   5   difficult to row. If she   6   for a moment, the tide would push the boat back
towards the   7  . She wasn't even halfway,   8   she was already tired and her hands   9   from pulling on
the rough wooden oars (船桨)." I'm never going to  10  it", she thought. She rested the oars on her knees
and  11  her head helplessly, then looked up as she  12  the boat shift (晃动) against the tide.
     The east wind, which had swung (旋转) around from the south-west,  13  her help and pushed the boat
towards the mountains. It was going to be  14 . Her hands weren't so painful. Her chest didn't feel as if it
was about to burst  15 .
     The lights of the town became  16 . One of the oars banged against the side of the boat and she  17  it
with a start. Had she been asleep, or just  18 ? She looked over her shoulder. She was almost on the beach.
The girl gave one last  19  on the oars to ground the boat, and then lay back against the seat. She listened to
the waves  20  and knew she had come home. Far across the moonlit bay the lights were no more than a
sparkling chain.

( )1. A. car    
( )2. A. beside   
( )3. A. another  
( )4. A. deep    
( )5. A. more    
( )6. A. slept   
( )7. A. home    
( )8. A. if     
( )9. A. hurt    
( )10. A. get    
( )11. A. turned  
( )12. A. saw   
( )13. A. got to  
( )14. A. difficult 
( )15. A. any more 
( )16. A. brighter 
( )17. A. destroyed
( )18. A. dreaming 
( )19. A. blow   
( )20. A. anxiously 		B. boat     
B. before    
B. other    
B. calm     
B. less     
B. continued  
B. mountains  
B. so      
B. ruined    
B. make     
B. dropped   
B. made                   
B. came to  
B. serious  
B. still more 
B. bigger   
B. threw   
B. guessing  
B. hit   
B. happily  		C. ship       
C. behind    
C. either       
C. gentle      
C. as      
C. rested       
C. south-west   
C. but       
C. troubled     
C. keep     
C. cocked       
C. heard    
C. sent for              
C. all right   
C. no more    
C. closer    
C. repaired   
C. inventing      
C. pull    
C. sadly     		D. sail                 
D. beyond               
D. the other              
D. rough                 
D. least                
D. rowed                  
D. entrance              
D. since                
D. broke                 
D. take                 
D. raised                 
D. felt               
D. reached for            
D. certain enough         
D. once more              
D. smaller                
D. seized                 
D. expecting               
D. strike               
D. carefully            
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