高級視聽說6-7原文-展示頁
2024-09-02 17:18本頁面
【正文】 In the Pacific Ocean, for example, a tsunami travels at a speed of up to 600 miles, or 970 kilometers, per hour. As the tsunami es close to the shore, however, the speed of the tsunami drops to about 100 miles (or 160 kilometers) per hour. That39。Chapter 6 Hydroponic Aquaculture: How One System Works The growing of plants without soil has developed from experiments carried out to determine what substances (like soil and water) make plants grow. Growing plants in water (rather than in soil) in other words, hydroponics dates back many more years than you might think. Scientists believe that hydroponics or aquaculture is at least as ancient as the pyramids of Egypt. Scientists also know that a primitive form of aquaculture has been used in the region of Kashmir for centuries. In fact, scientists believe hydroponic growing actually preceded soil growing. They even believe that using hydroponics as a farming tool started in the ancient city of Babylon with its famous hanging gardens. These hanging gardens were probably one of the first successful attempts to grow plants hydroponically.However, returning to more modern times, researchers at the University of the Virgin Islands have developed a system of hydroponic aquaculture that is both simple and low cost. The system uses gravity to create recirculating water systems in which fish are raised and vegetables are grown. Let me take a minute to explain the process of how this particular system of hydroponic aquaculture works on the island of St. Croix in the Virgin Island. To start with, rai
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