2018下半年pets2级阅读理解试题及答案

The idea of being able to walk on water has long interested humans greatly. Sadly, biological facts prevent us ever accomplishing such a thing without artificial aid --- we simply weigh too much, and all our mass pushes down through our relatively small feet, resulting in a lot of pressure that makes us sink.

However, several types of animals can walk on water. One of the most interesting is the common basilisk Basilicus basilicus, a lizard(蜥蜴)native to Central and South America. It can run across water for a distance of several meters, avoiding getting wet by rapidly hitting the water’s surface with its feet. The lizard will take as many as 20 steps per second to keep moving forward. For humans to do this, we’ll need huge feet that we could bring up to our ears in order to create adequate “hitting.”

But fortunately there is an alternative: cornflour. By adding enough of this common thickening agent to water (and it does take a lot), you can create a “non-Newtonian” liquid that doesn’t behave like normal water. Now if the surface of the water is hit hard enough, particles(粒子)in the water group together for a moment to make the surface hard. Move quickly enough and put enough force into each step, and you really can walk across the surface of an adequately thick liquid of cornflour.

Fun though all this may sound, it’s still rather messy and better read about in theory than carried out in practice. If you must do it, then keep the water wings handy in case you start to sink --- and take a shower afterward!

小题1:Walking on water hasn’t become a reality mainly because humans _______.A.are not interested in it

B.have biological limitations

C.have not invented proper tools

D.are afraid to make an attempt

小题2:What do we know about Basilicus basilicas from the passage?A.It is light enough to walk on water.

B.Its huge feet enable it to stay above water.

C.It can run across water at a certain speed

D.Its unique skin keeps it from getting wet in water

小题3:What is the function of the cornflour according to the passage?A.To create a thick liquid.

B.To turn the water into solid.

C.To help the liquid behave normally.

D.To enable the water to move rapidly.

小题4:What is the author’s attitude toward the idea of human’s walking on water?A.It is risky but beneficial.

B.It is interesting and worth trying

C.It is crazy and cannot become a reality

D.It is impractical; though theoretically possible

参考答案及解析

小题1:B

小题2:C

小题3:A

小题4:D

试题分析：

人类有一个一直感兴趣但一直未能实现的愿望：水上行走。不能实现的原因是“生物性局限”。本文主要介绍了一种理论上可行实际上难以实现的人类水上行走的方法：借助玉米粉(cornflour)增加水面浓度。

小题1:细节题。从第一段Sadly, biological facts prevent us ever accomplishing such a thing without artificial aid …可知，人类至今不能在水面行走是“生物”原因。选择B。

小题2:细节题。从第二段It can run across water for a distance of several meters, avoiding getting wet by rapidly hitting the water’s surface with its feet.一句可知，这种蜥蜴能在水面行走是因为速度快(每秒钟达到20步)。选择 C。

小题3:细节题。第三段this common thickening agent明确这是一种“常见的增稠剂”。选择A。

小题4:推断题。从第二段it does take a lot，最后一段it’s still rather messy and better read about in theory than carried out in practice. 等句推断，借助增稠剂实现人类在水面行走，理论上可行但真正实现很难做到。选择D项。