据报道，一次性木筷的发明专利属于日本，日本国内一次性木筷的消耗量也名列世界第一，但日本自己却从不生产这种产品，全部从国外进口．中国每年向日本出口200亿双优质木筷，而每制造1亿双木筷就要用去0.2万立方米的木材，而每立方米木材大约相当于4棵大树．请问中国每年向日本出口200亿双木筷，需要砍去多少棵大树？

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下列诗句中，描写气候的是（   ）

    Animals are our friends. We can find1different kinds of animals. Some animals are living 2 big woods(森林). And some animals are living with 3. Animals are very4 to people. People can teach the elephant to do some heavy 5. And they can also teach the dog to 6the house. A watch dog is very 7 It can help people in danger(危险). So people 8dogs very much. Most of9like to go to the zoo.10there are many animals in zoos. Zoo is a good place for children to get to know animals.