听力原文：Unless you have visited the southern United States, you probably have never heard

听力原文： Unless you have visited the southern United States, you probably have never heard of Kudzu. Kudzu, as any farmer in the south will sadly tell you, is a superpowered weed. It is a strong climbing plant. Once it gets started, Kudzu is almost impossible to stop. It climbs to the tops of the tallest trees. It can cover large buildings. Whole barns and farm houses have been known to disappear from view. Wherever it grows, its thick twisting stems are extremely hard to remove. Kudzu was once thought to be a helpful plant. Originally found in Asia, it was brought to America to help protect the land from being swallowed by the sea. It was planted where its tough roots which grow up to five feet long could help hold back the soil. But the plant soon spread to places where it wasn't wanted. Farmers now have to fight to keep it from killing other plants. In a way, Kudzu is a sign of labor shortage in the south. Where there is no one to work the fields, Kudzu soon takes over. The northern United States faces no threat from Kudzu. Harsh winters kill it off. The plant loves the warmth of the south, but the south surely doesn't love it. If someone could invent some use for Kudzu and remove it from southern farmland, his or her fortune would be assured.

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A．It has done more harm than good in the southern USA.

B．It was brought to the northern USA by Asian farmers.

C．It was introduced into the USA to kill harmful weeds.

D．It can be used by farmers to protect large buildings.