搜题请搜索小程序“爱下问搜题”
问题 选择题

下列叙述中正确的是[ ]

A．用玉米、植物秸秆等作原料制造乙醇，用作汽车的燃料

B．利用油脂在酸性条件下水解，可以生产甘油和肥皂

C．淀粉与纤维素分子式都为(C6H10O5)n而结构不同，所以它们互为同分异构体

D．1mol羟基含有电子数10NA

答案

答案：A

解答题

函数f（x）=-x2+2ax+1-a在区间[0，1]上有最大值2，求实数a的值．
查看答案
完形填空
完形填空
     A soldier returned to his castle at dawn.He was in a mess.His clothes were  1  ; his face was bloody;
his horse was lame.His 2met him at the gate,asking,"What has happened to you?"
       3  himself up as best he could,he replied,"Oh,Sir,I have been  4  in your service,robbing and burning
and killing your  5  to the west."
     "You have been what?"cried the  6  king,"But I haven't any enemies to the west!"
     "Oh!"said the soldier.And then,after a(n)  7  ,he continued to say,"Well,I think you do now."
     What about you? Do you have enemies to the west? Or in some other directions? None of us will
calmly sail through our lives in perfect  8  with everyone we meet.And though most struggles can be  9  
along the way,and most of our damaged  10  can eventually be healed,some issues may threaten to drive
a  11  wedge(楔) between people.Sincere moral and political ideas,especially,can  12  folks who just
hold different positions.
     One person said,"I don't have a personal enemy  13  .They've all died off.I  14  them terrible because
they helped define me."
     So-called"enemies"can  15  a valuable purpose.If we let them,they can teach us about ourselves.By 
 16  a mirror before us,they can help us  17  what we may have missed.By disagreeing with our ideas,they
can  18  our points of view.And,if we allow them,they can  19  help us practice strength and sympathy in
the face of criticism.
     If enemies cannot become friends,they can become  20  .If we listen,they will teach us what our friends
cannot.
( )1.A.old-fashioned
( )2.A.wife        
( )3.A.Tightening  
( )4.A.fighting    
( )5.A.enemies    
( )6.A.disappointed
( )7.A.sigh        
( )8.A.harmony    
( )9.A.won        
( )10.A.pains      
( )11.A.visible    
( )12.A.divide    
( )13.A.escaped    
( )14.A.respect    
( )15.A.achieve    
( )16.A.holding    
( )17.A.reflect    
( )18.A.sharpen    
( )19.A.clearly    
( )20.A.drivers    		B.clean      
B.father    
B.Straightening
B.training  
B.competitors
B.frightened
B.apology    
B.common    
B.settled    
B.wounds    
B.short      
B.isolate    
B.spared    
B.miss      
B.serve      
B.moving    
C.remember  
B.change    
B.immediately
B.teachers  		C.new        
C.king        
C.Pulling    
C.competing  
C.challengers
C.surprised  
C.rest        
C.touch      
C.made        
C.relationships
C.temporary  
C.disconnect  
C.left        
C.hate        
C.act        
C.choosing    
C.prove      
C.share      
C.unconsciously
C.doctors     		D.dirty       
D.friend      
D.Standing    
D.learning    
D.offenders   
D.excited     
D.pause       
D.company     
D.met         
D.bodies      
D.permanent   
D.separate    
D.stayed      
D.fear        
D.express     
D.giving      
D.see         
D.support     
D.publicly    
D.lawyers    
查看答案