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听力原文： You can tell the age of a tree by counting its rings. But these records of tree's life really say a lot more. Scientists are using tree rings to learn what's been happening on the sun's surface for the last ten thousand years. Each ring represents a year of growth. As a tree grows, it adds a layer to its trunk taking up chemical elements from the air. By looking up the dements in the rings from the given year, scientists can tell what dements were in the air that year. Dr. Stevenson is analyzing one element—earbon14 in rings from both living and dead trees. Some of the rings go back almost ten thousand years to the end of the Ice Age. When Stevenson followed the carbon14 trail back in time, he found carbonn4 levels change with the intensity of solar burning. You see the sun has cycles. Sometimes it burns fiercely and other times it is relatively calm. During the sun's violent periods, it throws off charged particles in fast moving strings called solar winds. The particles interfere with the formation of carbon14 co. Earth. When there's mom solar rand activity, less carbon14 is produced. Ten thousand years of tree fines show that the carbon 14 level rises and falls about every 420 years. The scientists concluded that the solar wind activity must fellow the same cycle.
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Acid rain means the precipitation in the form. of rain, snow or hail which is more acidic
From the text, we can infer that the most significant sign of Burberry is ______.
From there, the bags make their way in refrigerated trucks to thousands of McDonald's restaurants up and down the Eastern Seaboard. No more than 14 days after leaving the plant, the fruit will take the place of French fries in some child's Happy Meal. The apple slices, called Apple Dippers, are a symbol of how McDonald's is trying to offer healthier food to its customers？ And to answer the many critics who contend that most of its menu is of poor nutritional quality.
It remains to be seen whether these new offerings will assuage the concerns of public health officials and other critics of McDonald's highly processed fat and calorie—laden sandwiches, drinks and fries. So far, they have notat least not entirely. But this much is already clear: Just as its staple burgerandfries meals have made McDonald's the largest single buyer of beef and potatoes in the country, its new focus on fresh fruits and vegetables is making the company a major player in the $80 billion American produce industry.
The potential impact goes beyond dollars and cents. Some people believe that McDonald's could influence not only the volume, variety and prices of fruit and produce in the nation but also how they are grown.
According to the text, what will be found in some children's Happy Meal instead of French fries？
听力原文：M: John, how are you？ I heard you were sick.
W: They must have confused me with somebody else. I've never felt better.
Q: How does John feel？
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