【科学60秒】小蛀虫入侵，大钱财遭殃_英语听力练习mp3下载-科学-沪江听力酷

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【科学60秒】小蛀虫入侵，大钱财遭殃

听力简介：

Many wooden shipping crates that enter the U.S. contain hungry stowaways: invasive species of insects. Although these pests often ___1___ trees, they also ___2___ a different resource: money.

After dividing up the invaders into three categories based on their diet—some insects ___3___ wood while others chew foliage or slurp sap—researchers chose the most damaging species from each category. Then they analyzed the cost of these “poster pests” to five sectors: federal and local governments, households, residential property values and timber values. The non-native bugs cost local governments a whopping $1.7 billion every year, while also ___4___ $830 million dollars in residential property values. [Juliann E. Aukema et al., "Economic Impacts of Non-Native Forest Insects in the Continental United States," in PLOS One]

To keep the ravenous insects from causing more economic damage, one of the study’s authors, Juliann Aukema of U.C. Santa Barbara, urges stronger regulations on international trade. Bug-sniffing dogs might help. After all, they ___5___ keeping trees healthy.

—Sophie Bushwick
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