题干

二次函数y=
2
3
x2的图象如图所示,点A0位于坐标原点,点A1,A2,A3,…,An在y轴的正半轴上,点B1,B2,B3,…,Bn在二次函数位于第一象限的图象上,点C1,C2,C3,…,Cn在二次函数位于第二象限的图象上,四边形A0B1A1C1,四边形A1B2A2C2,四边形A2B3A3C3,…,四边形An﹣1BnAnCn都是菱形,∠A0B1A1=∠A1B2A2=∠A2B3A3=…=∠An﹣1BnAn=60°,则A1点的坐标为____ ,菱形An﹣1BnAnCn的周长为 ____ .

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(0,1),4n

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    The insects are important to farmers. When a honeybee lands on a flower in plant, pollen (花粉) sticks to its legs. When the bee lands on another flower, some of the pollen falls off and fertilizes the second plant.

    The act of spreading pollen is responsible for many fruits, vegetables, nuts and other crops. Yet about 30 percent of honeybees in the United States and other areas have died in recent years.

    Mike Leggett is a researcher at the University of Maryland. He wants to learn why so many bees are dying. “The number of colonies (蜂群) that die every winter has been one in three. So on average 30 percent of the colonies have died every winter over the last six winters. And that's a huge number.” His research team examined the pollen that honeybees carried to their homes. They found that the pollen contained high levels of 35 different pesticides (杀虫剂), which are chemicals used to protect plants. “Pesticides are used, and have been used, pretty widely, for centuries, to protect plants from diseases,” says Mr Leggett.

    Keith Oh linger, a farmer and beekeeper in Maryland, has watched many of his bees die every winter. Mr Ohlinger thinks widespread bee death is caused by several things happening at once. But he does not feel sure that pesticides are a part of the problem, “I felt it was the result of a lot of little things. I didn't feel that there was probably one smoking gun. But there's a division (分歧) there, some people feel that it is just one thing.”

    Honeybees are important to agriculture. This makes the search for an answer to their death very important for Mr Leggett's team. As he knows, one in every three bites of food we eat is somehow pollinated by honeybees.