题型:阅读选择 题类: 难易度:困难
山东省济宁市2024年中考英语试题
Sometimes when the rain falls hard and fast on you, it might hurt a little. But what happens when it hits a mosquito(蚊子)?
In 2012, David Hu, a scientist at Georgia Tech, became interested in this problem and decided to do a research. He used a high- speed camera so that he could watch the mosquitoes in very slow motion and find out what they' re doing when they' re out in the rain.
What he found is that when a raindrop falls on a mosquito, it's like when a bus hits a person. Besides, the little insect(昆虫) is hit by a raindrop about once every 20 seconds. So why don't we see many dead mosquitoes after it rains?
A mosquito is as big as a raindrop, but it is much lighter—0.002g only. This saves its life in raindrop hits. Because the mosquito is so light, when it is hit by a raindrop, it won't experience a force that is strong enough to kill it.
The study also found that when a mosquito is hit by a raindrop, the insect is pushed by the raindrop and falls together with it. But the mosquito doesn't get wet easily because it is covered with hairs which keep off water. After dropping about 6 cm, it will roll off the raindrop and fly away.
However, this trick isn't always successful. If the mosquito flies too low when it is hit by the raindrop, it won't have time to fly off. Then it will hit the ground and meet its death.
There are about 300 Asian (亚 洲 的) elephants in China now. They're in great danger, so we should learn more about Asian elephants to protect them better.
Weight:2, 300 to 4, 600 kg. Height(高度):261 cm to 289 cm. Look: Large ears, small eyes and a long trunk. Trunk: They use trunks to drink water, get food or make a sound. Food: They don't eat meat. They eat about 390 kinds of plants. |
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