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课时规范训练(单独成册) 训练(三十) Ⅰ.阅读理解 阅读下列短文，从每题所给的四个选项(A、B、C、D)中，选出最佳选项。 A Around the world，honeybee groups are dying in huge numbers：About onethird of nests collapse each year.For bees and the plants they pollinate (授粉)—as well as for beekeepers，farmers，honey lovers and everyone else who appreciates this marvelous social insect—this is a catastrophe. Honeybee collapse has been particularly worrying because there is no one cause，but rather a thousand little cuts.The main elements include the mixed impact of pesticides (杀虫剂) applied to fields，as well as pesticides applied directly into nets to control bugs，pests and diseases；nutritional shortages caused by vast acreages of singlecrop fields that lack diverse flowering plants；and commercial beekeeping itself，which destroys groups by moving most bees around the country multiple times each year to pollinate crops. The real issue，though，is not the volume of problems，but the interactions among them.Here we find a major lesson from the bees that we ignore at our risk：the concept of synergy (协同作用)，where one plus one equals three，or four，or more.A typical honeybee colony contains remains from more than 120 pesticides.Alone，each represents a benign dose (良性剂量)．But together they form a poisonous soup of chemicals whose interplay (相互作用) can greatly reduce the effectiveness of bees’ immune systems，making them easier to suffer from diseases. | 
