问题 填空题

整理一批图书,由一个人做要40小时完成,现计划由一部分人先做4小时,再增加2人和他们一起做8小时,完成这项工作,假设这些人的工作效率相同,具体应先安排多少人工作?设先安排x人工作,可列方程:______.

答案

设应先安排x人工作,

根据题意得:

4x
40
+
8(x+2)
40
=1

故答案为:

4x
40
+
8(x+2)
40
=1

完形填空
完形填空。
     We know that trees are useful in our everyday life. They __1__ us many things, such as wood,
 oxygen, rubber, medicines and many other things. They can __2__ tell us a lot about our climate. The
  following are the reasons. If you __3__ a tree, you can see that it has many rings. Most trees grow one
  new ring __4__ year. Because of the reason, we know __5__ a tree is. A tree over a hundred years old
  means that it has more than a hundred __6__ . When the climate is dry or very cold, the trees do not
 grow very much and their rings are usually __7__ . When it is wet and warm, the rings are much
  thicker. If the rings are suddenly very thin or suddenly very thick, this means that the __8__ changed
  suddenly. If we look at the rings on this tree, we can learn about the __9__ for a hundred years. We
 can see __10__ our climate is changing today.
(    ) 1.A.tell  
(    ) 2.A.not  
(    ) 3.A.cut across
(    ) 4.A.every  
(    ) 5.A.how big  
(    ) 6.A.trees  
(    ) 7.A.big  
(    ) 8.A.climate
(    ) 9.A.people  
(    ) 10.A.how    
B.ask  
B.too  
B.climb up
B.many
B.how long
B.leaves
B.thick
B.trees
B.things
B.why  
C.give  
C.to    
C.walk past
C.the first
C.how old
C.people  
C.small
C.rings
C.climate
C.when  
D.get          
D.also        
D.look at      
D.from        
D.how much    
D.rings        
D.thin        
D.animals      
D.life        
D.while        
单项选择题