题干

下列关于生物与环境的叙述,错误的是        

A:在生态系统中,碳以二氧化碳的形式在生产者、消费者和分解者之间
循环

B:猫头鹰和黄鼬捕食田鼠,猫头鹰和黄鼬有竞争关系

C:生产者固定的太阳能的总量便是流经这个生态系统的总能量

D:化石燃料的大量燃烧,使大气中SO2过多,是形成酸雨的主要原因之

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答案(点此获取答案解析)

A

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完形填空。

阅读下面短文,从短文后各题所给的四个选项(A、B、C和D)中,选出可填入空白处的最佳选项。

    As I walked down the hall on the last day of the school year, I watched wide-eyed as my fellow students 1their drawers into the dustbins in front of the hall. Paper flew in all directions; broken shelves were 2 everywhere.

    Suddenly, I came up with an idea: my school really needed a 3 programme. I believed that one person could make a 4so I wrote out my recycling5 As I told the schoolmaster about my 6 my heart was beating wildly.

    With her agreement and encouragement, I would 7 cardboard boxes in the library, offices and classrooms to 8 papers, magazines and newspapers.

    That night, I designed a dozen 9and planned to arrive at school early to stick them up and hand out 10to classrooms on Monday. But when I arrived, I was very disappointed-the night-watchman had 11down all of the cardboard boxes I had saved. I was so upset. I began searching for other boxes, but I met with 12 success.

    A few days later,13 my English teacher took me into the new computer lab, and before my eyes sat a 14of cardboard boxes. I am sure I was the 15 person in the world when I saw these boxes. These were the boxes that the new computers had arrived in, and they were the16size.

    I rolled my recycling rubbish bins to the dining room, stuck up my posters, and17made an announcement18 the loudspeaker, letting the whole school know they now had a(n)19 about what would happen to their unwanted papers, cans and bottles.

    Since that day, recycling has become part of everyday life at my school. Students and teachers now take active 20 to save trees and other natural resources.