A
Number sense is not the ability to count.It is the ability to recognize a__1__in number. Human beings are born with this ability.__2__，experiments show that many animals are，too.For example，many birds have good number sense.If a nest has four eggs and you remove one，the bird will not__3__．However，if you remove two，the bird__4__leaves.This means that the bird knows the__5__between two and three.
Another interesting experiment showed a bird's__6__ number sense.A man was trying to take a photo of a crow(乌鸦)that had a nest in a tower，but the crow always left when she saw him coming.The bird did not__7__until the man left the tower. The man had an__8__．He took another man with him to the tower.One man left and the other stayed，but they did not__9__the bird.The crow stayed away until the second man left，too.The experiment was __10__with three men and then with four men.But the crow did not return to the nest until all the men were__11__．It was not until five men went into the tower and only four left that they were__12__able to fool the crow.
How good is a human's number sense? It's not very good.For example，babies about fourteen months old almost always notice if something is taken away from a__13__group.But when the number goes beyond three or four，the children are__14__fooled.
It seems that number sense is something we have in common with many animals in this world，and that our human__15__is not much better than a crow's.
1．A.rise B．pattern
C．change D．trend
2．A.Importantly B．Surprisingly
C．Disappointedly D．Fortunately
3．A.survive B．care
C．hatch D．notice
4．A.generally B．sincerely
C．casually D．deliberately
5．A.distance B．range
C．difference D．interval
6．A.amazing B．annoying
C．satisfying D．disturbing
7．A.relax B．recover
C．react D．return
8．A.appointment B．excuse
C．idea D．explanation
9．A.fool B．hurt
C．catch D．kill
10．A.reported B．repeated
C．designed D．approved
11．A.confused B．gone
C．tired D．drunk
12．A.gradually B．luckily
C．strangely D．finally
13．A.single B．small
C．local D．new
14．A.seldom B．temporarily
C．merely D．often
15．A.sight B．nature
C．ability D．belief
【语篇解读】 本文是说明文。讲述什么是数字感之后重点介绍有关动物也具有数字感的实验，实验结果表明许多动物和人一样具有数字感，且人的这种感知数字变化的能力并不比乌鸦的这种能力强多少。
1．解析：由下文的两个实验来看，都是数字的“变化”。故选C项。
答案：C
2．解析：由句意“实验表明许多动物也跟人类一样具有这种能力”，可知这是“令人惊讶的”，故选B。
答案：B
3．解析：结合下句，特别是However可知，上下句的大意应是“如果鸟巢内有四个蛋，你移走一个蛋，这只鸟会没有注意到；然而，如果你移走两个蛋，这只鸟就会离开这里了”。故选D。
答案：D
4．解析：这只鸟“通常”会离开，因为这个具体的例子是用来说明“many birds have good number sense”这个主题的。故选A。
答案：A
5．解析：这个例子谈到，四个中移走一个余下三个，这只鸟不会注意到；若移走两个，余下两个，这只鸟就会离开这里了。这说明这只鸟知道余下两个与余下三个的“差别”。故选C。
答案：C
6．解析：与上文中good number sense(良好的数字感)中的good相对应．也与第2题的答案surprisingly相对，故选“amazing(令人惊异的)”，近义复现。
答案：A
7．解析：与left相对，“离开”“返回”这两者也叫同现；与下文中“return to the nest”的return是原词复现。
答案：D
8．解析：从下文看，这个人有了一个“主意”或想了一个“办法”。故选C。
答案：C
9．解析：由but可知，他们并没能够“欺骗”那只乌鸦。与下文“fool the crow”中的fool是原词复现，故选A。
答案：A
10．解析：该实验先由一个人去接近那只乌鸦，然后又带一个人即共两个人去做这个实验，接着三个人、四个人去“重复”做这个实验。故选B。
答案：B
11．解析：那只乌鸦直到所有人都“不在了，消失了”才会回来。
答案：B
12．解析：前面已分别由一个人、二个人、三个人、四个人重复做了四次了，直到五个人进了塔走了四个，即还有一个在塔里，他们才“最终”欺骗了这只乌鸦。结合文章倒数第二段讲14个月大的婴儿在数量超过三四个之后就常常被欺骗，就可理解。
答案：D
13．解析：由下文“But when the number goes beyond three or four”可知，是指三四个以内的这样一“小”组东西。
答案：B
14．解析：由But可知，后文是表示与always notice相对的意思，当数量超过三四个以后，就“常常”能欺骗这些婴儿了。故选D。
答案：D
15．解析：由文章的首段或首句可知，本文在讲到人与动物具有数字感，即有辨别数字变化的“能力”。故选C。
答案：C
