问题 单项选择题

关于化学位移伪影,错误的是()

A.是指由化学位移现象导致的图像伪影 

B.主要出现在频率编码方向上 

C.脂肪组织的信号向频率编码梯度场强较低的一侧移位 

D.场强越高,化学位移越明显 

E.改变频率编码方向能减轻或消除化学伪影 

答案

参考答案:E

完形填空
完形填空。
        If we were asked exactly what we were doing a year ago, we should probably have to say that we could
not remember. But if we had    1     a book and had written in it an account (叙述) of what we did each day, we
should be able to give an answer to the question. 
        It's the     2     in history. Many things have been     3     because we do not have any written account of
them. sometimes men did    4     the most important happenings in their country, but often the material was
destroyed by fire or in a war. Sometimes there was never any written record at all     5     the people of that time
and place did not know    6     to write. For example, we know a good deal about the people who lived in China
4,000 years ago,because they could write and leave written records for those who lived     7     them. But we
know almost nothing about the people who lived even 200 years ago in central Africa, because they had not
learned to write. 
         Sometimes, of course,     8     the people cannot write, they may know something of the past. They have
heard about it from older people,and often songs and dances and stories have been made about the most
important happenings, and these have been sung and acted and told for many    9    . For most people are proud
to tell what their fathers did in the past. Such     10     stories are often very helpful where there are no written
records.
( )1.A.bought    
( )2.A.question  
( )3.A.forgotten 
( )4.A.experience
( )5.A.although  
( )6.A.how       
( )7.A.on        
( )8.A.while     
( )9.A.people    
( )10.A.long     
B.written     
B.same       
B.checked    
B.know       
B.when     
B.what       
B.by           
B.since       
B.generations 
B.different
C.kept      
C.story      
C.damaged   
C.study      
C.unless   
C.when      
C.after       
C.even if    
C.reasons    
C.personal
D.opened      
D.mystery     
D.imagined    
D.record      
D.because   
D.why           
D.with         
D.as long as   
D.purposes     
D.spoken 
单项选择题