高級視聽說6-7原文(編輯修改稿)
2025-09-14 17:18 本頁面
【文章內(nèi)容簡介】 then the hydroponic process starts all over again. The aquaculture scientists say that this relatively simple system produces about 25,000 heads of lettuce, and one ton of fish in a year from just one 3,000gallon fish tank. A mercial pany would need to have several tanks in order to make the process profitable, but researchers at the University of the Virgin Islands have demonstrated exactly how aquaculture can be used to grow plants without using soil. The process could help some countries that are looking to develop new methods to produce food in “soilless culture”. Just to give an example, in the case of tomatoes, dirt farmers raise about 3,500 plants per acre. In hydroponics, the tomato plants can be placed much closer together, and it’s possible to cultivate as many as 10,000 plants on an acre of land. In the future, we will probably see more and more agriculture being done as hydroponic aquaculture. And many consumers won’t know the difference.Listening factoid 1The jackfruit tree of southern Asia bears the world39。s largest tree fruits. The fruits can weigh as much as 110 pounds. As many as 250 fruits are produced by a single tree each year. People in India and Sri Lanka eat the fruit fresh or make a syrup out of this large fruit. Would you like to eat the jackfruit?Listening factoid 2Did you know that the Aztecs of Central America did hydroponic gardening long ago? How did they do it? First, they built rafts of rushes and reeds tied together with tough roots. Then they dredged up soil from the shallow bottom of the lake, and pil
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