听录音，回答以下问题：
What might heln control global warming according to American researehers7

  It's been a woe cry for environmentalists in recent years "Mass deforestation contributes to global warming". But that argument may now have to be revised. Scientists in the United States have run a simulation of the effects of large-scale clearing. And they find that if trees were to be cut down in icy northern regions, it would actually cool down the Earth. The reason: Snow reflects sunlight and the great pine forests of Russia(Europe and Canada shade tens of thousands of hectares of reflective snow.
根据题千中出现的control olglUMwarming，可以判断新闻报道了有关控制全球变暖的措施。
据美国研究人员称，砍掉雪域的树木可以帮助抵御全球变暖的影响。
B。本题是对新闻事件中重要信息的考查。新闻提到，美国研究者称，砍掉雪域的树木可以帮助抵御全球变暖的影响，故本题选B。