Bamboo is one of the world’s most useful plants. For thousands of years bamboo has been used in many different ways—from food to medicine to clothing and, in small ways, as a building material.
However, bamboo is not often used as a building material in the developed world. A professor at the University of Pittsburgh in Pennsylvania is trying to change that. The professor and his students are testing the strength of bamboo. They are testing its radial load, or how much pressure or weight it can take before breaking. Kent Harries is a professor at the University of Pittsburgh. Harries says that testing methods for bamboo needs to be the same for all. They need to be standardized.
Harries says bamboo is strong in nature. The strength of at least three species of bamboo is similar to steel. Besides its strength, Harries says that bamboo has other features that make it a great building material. He says it is resilient, meaning it keeps its shape and strength even under pressure.
Bamboo also grows quickly. Bamboo that is suitable for construction needs much fewer resources than wood. The harvest cycle of bamboo is about 3 years. Softwoods such as cedar, pine and spruce have a harvest cycle of about 10 years. And hardwoods that come from flowering plants such as oak, maple and walnut need more than 30 years.
Bamboo is widely used as food for pandas. It is also used for flooring and window covers. However, for building, bamboo is not used much outside its native growing area. This is mostly because of its round shape. But there are other reasons too. People think that bamboo is a low-quality building material.
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相似题推荐
1．古树保护的意义；2．古树保护面临的问题；3．你的建议。
注意：1．词数100左右；2．可以适当增加细节，以使行文连贯。
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When people think of plants, they usually think of gardens, parks, or even jungles. One place that does not usually come to mind is the desert. However, some deserts contain many plants that are able to grow and survive under difficult conditions.
Deserts can reach temperatures of 50 degrees or more in the daytime and can also drop below 0 degrees at night. This is a huge temperature difference under which desert plants have to live. Besides the high and low temperatures, all deserts receive very little water in the form of rain; sometimes it doesn’t rain for months. So, how do desert plants get water when there is no rain?
There are three main ways plants survive in the desert. First, some desert plants grow without leaves. Others have developed special ways of storing whatever water they can find, such as growing a waxy leaf covering that helps keep water inside the leaf. These plants can survive for weeks or months on the water collected from just one rainfall.
A second way desert plants survive even in the most difficult conditions is by growing very long roots. These roots spread out and search for any water they can find. Once they find water, the roots suck up as much as they can and then hold it, only allowing the plant above the ground to have small amounts at a time.
The third way plants survive in the desert is by “sleeping”. Some plants can turn off almost all their processes and just remain inactive, almost as if dead, while they wait for rain. When the rain does come, they quickly drink up every drop they possibly can and burst back into activity.
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1. 写信目的；
2. 分析原因并提出建议；
3. 你的呼吁；
注意：
1. 写作词数应为80左右;
2. 可以适当增加细节，以使行文连贯。
参考词汇： 生物多样性biology-diversity
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The School English Club
