下列有关叶片所受应力的说法中有误的一项是:()A.叶片中的应力是由叶片的离心力和气动

题型:单项选择题

问题:

下列有关叶片所受应力的说法中有误的一项是:()

A.叶片中的应力是由叶片的离心力和气动力引起的。

B.因叶片离心力而产生的应力数值是比较大的,它构成了叶片应力的主要组成部分,这个应力是恒定不变的。

C.因气动力而在叶片中引起的弯曲应力,其数值很小,可忽略不计。

D.因气动力引起的弯曲应力是脉动的,会引起叶片材料发生疲劳破坏。

考点:发电工(动力工)发电工(动力工)中级发电工(动力工)中级题库
题型:单项选择题
完形填空。
     I remember that when I was in my teens,I used to refuse  to  follow the many"dos"and"don'ts"of my
parents.For example,when I planned to sleep with my pet dog, they immediately said ,"   1  "because
they thought it was dangerous.This was just an example of the things I thought my parents were    2  
about.        
     Today,however,I am the father of a boy aged 15,and I find that I too,am pressuring my son with a
lot of    3    that are hard for him.
     The   4    day,I noticed that my son was wearing  giant  pants  that could    5   three teenagers.  No
one should wear them.I commanded  him  to take them off at once . Usually,he 6   me, but this  time
he put his foot down."What's  wrong with giant pants ? 7   classmates  wear them. And I don't think
you have the right to ask me to remove them,  8  you are my father !" said he.I    9   realized that we
are now living in a society with more freedom,and that my son's strong will on wearing giant pants was
just an  10  of the generation gap(代沟) between us.Therefore,   I gave in and now he is still wearing
giant pants.
( )1. A.Stay up    
( )2. A.unreasonable
( )3. A.jobs    
( )4. A.another    
( )5. A.put    
( )6. A.allowed    
( )7. A.All my    
( )8. A.after all  
( )9.     A. possibly    
( )10.   A.instance  
B.Come along  
B.unforgettable
B.rules    
B.other    
B.wear    
B.annoy    
B.My all    
B.only if    
B.suddenly    
B.challenge    
C.No way
C.unbelievable
C.notes  
C.others  
C.stay    
C.argues  
C.All the my
C.even though
C.especially  
C.resolution  
D.No problem    
D.uncomfortable
D.habits        
D.other's      
D.hold          
D.obeys        
D.My all the    
D.as for        
D.extremely    
D.assessment    
题型:单项选择题

脾气虚的辨证要点是

A.腰膝酸软,神疲乏力,耳鸣失聪,小便频数而清
B.腰膝酸软而痛,眩晕耳鸣,齿松发脱,五心烦热,潮热盗汗
C.成人早衰,耳鸣耳聋,健忘恍惚,两足痿软,发脱齿摇
D.身体浮肿,腰以下尤甚,按之没指,畏寒肢冷,腰膝酸冷
E.面色白或黧黑,腰膝酸冷,形寒肢冷,下肢为甚,神疲乏力

题型:单项选择题

下列说法正确的是[ ]

A.锐角一定等于它的余角

B.钝角大于它的补角

C.锐角不小于它的补角

D.直角小于它的补角

题型:单项选择题

应用眼专业超声诊断可探测: ①视网膜剥离; ②玻璃体出血; ③视神经异常()

A.①+②+③

B.①+③

C.①

D.①+②

题型:单项选择题

以市场需求为导向,优化区域布局,建设农产品产业带,发展特色农业是我国农业可持续发展的重要途径之一。下面是我国两大重要的商品农业生产基地,读图,回答下列问题。

(1)下表反映甲、乙两区域平原地区农作物的差异性,试分析这一差异产生的主要自然原因。

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(2)从自然角度考虑,图中乙区域C、D平原农业发展的主要制约因素是________。

(3)图中甲区域的农业发展与乙区域相比,有哪些优势区位条件?

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