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托福听力练习-科学美国人60秒:蓝莓驯化

2017-04-26 10:59:00来源：科学美国人60秒

点击查看>>科学美国人60秒音频：蓝莓驯化

　　科学美国人60秒听力练习：蓝莓驯化

　　科学美国人60秒英文文本

　　Mmmm, blueberries. It’s the height of the season, and I’ve been tossing a handful onto cereal, into pancakes or just straight into my mouth. Many of our crops were cultivated thousands of years ago, and we don’t know the individuals responsible. Not so for blueberries. Because the blueberry wasn’t domesticated until just about a century ago. And we have a botanist named Fred Coville to thank.

　　In 1912 if you wanted blueberries, you picked the wild variety. And it was devilishly difficult to get the plants to grow anywhere but where they were naturally found. Coville figured out after many dead ends that blueberries need exceedingly acidic soil: most plants like the soil at a neutral pH of about 7. Blueberries do best when the pH is about 4.5.

　　Colville also determined that blueberries can’t self-fertilize, so the grower must make sure the crop can be cross-pollinated. His research efforts are described in an article in the U.S. Department of Agriculture magazine Agricultural Research. [Kim Kaplan, Blueberry Growing Comes to the National Agricultural Library]

　　So next time you pop a blueberry, don’t forget to thank Fred.

　　—Steve Mirsky

　　中文翻译请点击下一页

本文关键字: 托福听力 科学美国人60秒

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