问题 填空题

已知a>b,如果a2-b2,2ab是三角形较小的两条边,那么当第三边等于______时,这个三角形是直角三角形.

答案

设第三边等于x时,这个三角形是直角三角形,

则x=

(a2-b2)2+(2ab)2
=a2+b2

故答案为:a2+b2

完形填空
完型填空
     In the past, people didn't use stamps. They had to pay money when they received letters. Rowland Hill,
a schoolmaster in England was the first    1    using stamps. He thought it    2    much easier for people to use
   3   . They could go to the nearby    4    to buy stamps and put them on envelopes(信封)    5    they    6    letters.
The post office only put seals(印章)    7    the stamps so that people could not use the stamps    8   . In this way,
the post office    9    send postmen to collect(收) money. It only needed    10    postmen to deliver(投递) letters.
The government finally accepted(接受) the good idea.
( )1. A. to think  
( )2. A. could be  
( )3. A. a stamp    
( )4. A. a shop    
( )5. A. after      
( )6. A. sent      
( )7. A. in        
( )8. A. again      
( )9. A. need not to
( )10.A. few
B. thinking      
B. will be      
B. stamps        
B. school        
B. before        
B. send          
B. over          
B. too          
B. didn't need to
B. fewer
C. to think of  
C. is          
C. stamp        
C. village      
C. in          
C. to send      
C. on          
C. either      
C. needed not to
C. many
D. think about
D. was        
D. stampes    
D. post office
D. with      
D. sended    
D. above      
D. also      
D. didn't need
D. much
单项选择题