函数y=log2(-x2+2x+7)值域是______.

题型:填空题

问题:

函数y=log2(-x2+2x+7)值域是______.

考点:函数的单调性、最值对数函数的解析式及定义(定义域、值域)
题型:填空题

在某药物的临床试验中为使两组具备充分的可比性,消除选择偏倚和混杂偏倚的影响,研究者以研究对象的病历号进行随机分配,这种随机化方法称为()。

A.完全随机化

B.区组随机化

C.分层随机化

D.系统随机化

E.未作随机化

题型:填空题

下列项目中,()不是衡量数据传输系统好坏的重要指标。

A.传输速率

B.差错率

C.使用率

D.可靠性

题型:填空题

男性,16岁,因患肺炎,给予青霉素治疗。经青霉素皮试为(-)。随即肌内注射青霉素,但注射后立即出现面色苍白,全身湿冷,血压测不到,此时应给何药进行紧急处置()

A.肾上腺素

B.间羟胺

C.苯海拉明

D.去甲肾上腺素

E.异丙嗪

题型:填空题
完形填空。

     My 14-year-old son, John, and I spotted the coat at the same time. It was hanging at a (an)   1   clothing
store. The coat had a black velvet collar, delightful tailoring, a Fifth Avenue label (标签) and a (an)   2   price
of $ 28.
     We looked at   3  , saying nothing,   4   John's eyes shone. Dark, woolen topcoats were popular just then
with   5   , but could   6   several hundred dollars now.
     John   7   the coat. He turned from side to side, eyeing himself in the mirror with a serious, studied   8 
 that soon changed into a smile. The   9   was perfect. John wore the coat to school the next day and came
home wearing a big smile. "How did the kids like your coat?" I asked. "They love it."  He said, carefully  10 
it over the chair and smoothing it flat.
     Over the next few weeks, the   11   came over John. Quiet, reasoned discussion was   12   argument. He
became more thoughtful and eager to  13  . "Good dinner, Mum,"  he would say every evening. One day when
I suggested that he might start on homework before dinner, John said, "You are right, and I guess I will."
     When I  14   this to one of his teachers and remarked that I didn't know   15   caused the changes, she
said with laughter, "It must be his coat!" At the library, we  16   to meet a friend who had not seen our children
for a long time. "   17   this be John?" he asked, looking up to John's new height, assessing the cut of his coat,
and extending his hand, one gentleman to another.
     John and I both knew we should never   18   a person's clothes for the real person within them. But there
is something to be said for   19   a standard of excellence for the world to see, for practicing standards of excellence in thought, speech and behavior, and for  20   what is on the inside with what is on the outside.

( )1. A. second-hand 
( )2. A. reasonable  
( )3. A. each other  
( )4. A. therefore   
( )5. A. adults     
( )6. A. spend       
( )7. A. touched    
( )8. A. gesture                  
( )9. A. color      
( )10. A. pressing  
( )11. A. happiness  
( )12. A. because of  
( )13. A. please     
( )14. A. mentioned  
( )15. A. when       
( )16. A. happened   
( )17. A. Should    
( )18. A. watch     
( )19. A. doing     
( )20. A. comparing  
B. expensive     
B. unbelievable  
B. one another   
B. however      
B. people        
B. cost                       
B. buttoned      
B. expression    
B. price         
B. taking       
B. satisfaction  
B. instead of    
B. regret       
B. wrote        
B. how     
B. came    
B. Would     
B. judge    
B. showing   
B. connecting  
C. big              
C. special          
C. the other        
C. but               
C. parents         
C. pay              
C. held             
C. attitude        
C. fit                           
C. hanging         
C. change           
C. aware of         
C. complain         
C. reported         
C. what            
C. intended         
C. Must            
C. mistake          
C. speaking         
C. combining      

D. cheap                   
D. average                 
D. others                 
D. thus                    
D. teenagers               
D. take                     
D. obtained                
D. feeling                
D. style                   
D. folding                
D. generosity              
D. full of                 
D. apologize               
D. explained              
D. that                   
D. decided                
D. Could                  
D. consider               
D. wearing                    
D. matching       

题型:填空题

磁电机开关关闭后,发动机继续动转的可能原因是()?

A.磁电机定时错误;

B.进气管道有裂纹;

C.磁电机开段接地线断开。

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