题目

Andy lived high in the Rocky Mountains. He hunted (打猎)wild animals there and he also took other men hunting. That was his work.One day a letter brought Andy a new job. This job changed both his feeling about animals and his way of hunting. The letter said: I want to write a story about bighorn sheep. I need pictures to go with my story. Will you get pictures of the sheep for me?Andy’s two sons wanted their father to take the job. “We will help you!” they said. Bighorn sheep are very wild. Andy knew it would be hard to get their pictures. “But why not try?” they said.For days, And下面关于碳循环的说法中，错误的是A.生物群落中的碳元素主要是依靠光合作用固定的B.温室效应主要是由于化石燃料的大量燃烧造成的C.在生态系统中，碳元素在无机环境和生物群落间循环的主要形式是碳酸盐D.碳循环过程中伴随着能量流动