VOA慢速英语2015.08.25 effort, plants, problem, collected, future

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But he says there is a problem. He says many wild versions of farmed plants are disappearing. He says they are threatened and scientists have not collected their seeds for future use._____________________但他说还有一个问题.许多植物的野生种品种正在消失.它们濒临绝种,科学家们没有采集到供未来使用的种子.________________________

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