题目内容
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!
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
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
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.
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
1.B
2.C
3.A
4.D
【解析】
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。
1.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。
2.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。
3.this common thickening agent 明确这是一种“常见的增稠剂”。选择A。
4.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。
考点:说明文。
A device that stops drivers from falling asleep at the wheel is about to undergo testing at Department of Transport laboratories and could go on sale within 12 months.
The system, called Driver Alert, aims to reduce deadly road accidents by 20% - 40% that are caused by tiredness. Airline pilots can also use it to reduce the 30% of all pilot-error accidents that are related to fatigue.
Driver Alert is based on a computerized wristband (腕套). The device, worn by drivers or pilots, gives out a sound about every four minutes during a car journey. After each sound the driver must respond by squeezing the steering wheel (方向盘). A sensor in the wristband detects this pressing action and measures the time betweenthe sound the driver’s response.
Tiredness is directly related to a driver’s response time. Usually, a watchful driver would take about 400 milliseconds to respond, but once that falls to more than 500 milliseconds, it suggests that the driver is getting sleepy.
In such cases the device gives out more regular and louder sounds, showing that the driver should open a window or stop for a rest. If the driver’s response continues to slow down, the sounds become more frequent until a nonstop alarm warns that the driver must stop as soon as possible.
The device has been delivered to the department’s laboratories for testing. If these tests, scheduled for six months’ time, are successful, the makers will bring the product to market within about a year.
1.According to the text, Driver Alert ______.
A. aims to reduce tiredness-related accidents
B. has gone through testing at laboratories
C. aims to prevent drivers form sleeping
D. has been on sale for 12 months
2.How should a driver respond to the sounds from Driver Alert?
A. By sounding a warning.
B. By touching the wristband.
C. By checking the driving time.
D. By pressing the steering wheel.
3.We can learn form the text that the driver needs to stop for a break when his response time is ____.
A. about 400 milliseconds B. below 500 milliseconds
C. over 500 milliseconds D. about 4 minutes
4.When the driver gets sleepy while driving, Driver Alert ______.
A. moves more regularly
B. stops working properly
C. opens the window for the driver
D. sounds more frequently and loudly