【PTE真题音频+文本】RL&SST 真题音频系列108:Rice

【墨尔本PTE】【 PTE真题】PTE听力和口语一直是PTE口语考试中最重要的部分,今天墨尔本文波PTE培训学校给大家总结下PTE中的RL真题:


In 1943, what became known as the Green Revolution began when Mexico, unable to feed its growing population, shouted for help. Within a few years, the Ford and Rockefeller Foundations founded the International Rice Research Institute in Asia, and by 1962, a new strain of rice called IR8 was feeding people all over the world. IR8 was the first really big modified crop to make a real impact on world hunger. In 1962 the technology did not yet exist to directly manipulate the genes of plants, and so IR8 was created by carefully crossing existing varieties: selecting the best from each generation, further modifying them, and finally finding the best. Here is the power of modified crops: IR8, with no fertilizer, straight out of the box, produced five times the yield of traditional rice varieties. In optimal conditions with nitrogen, it produced ten times the yield of traditional varieties. By 1980, IR36 resisted pests and grew fast enough to allow two crops a year instead of just one, doubling the yield. And by 1990, using more advanced genetic manipulation techniques, IR72 was outperforming even IR36. The Green Revolution saw worldwide crop yields explode from 1960 through 2000.


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