题干

下列关于生态学问题的叙述中不正确的是

A:大力植树造林,改善能源结构,提高能源效率,是缓解温室效应的最佳途径

B:被有机物轻度污染的流动水体中,距排污口越近的水体中溶解氧越多,N、P等无机盐也越多

C:保护生物多样性,是维持生态系统稳定性的措施之一,体细胞克隆等为之提供了技术支持

D:当水和土壤被重金属污染时,营养级越高的消费者体内的重金属含量越高

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B

同类题4

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    I grew up in New Hampshire, a small town in South Canada, where in my father's words for the seasons were “Spring, Summer, Fairtime and Winter!”At that time, a week-long fair was held in the town every autumn. Thousands of people from other towns came to sell and buy things. It was the busiest time of the year.

    When “Fairtime” came, my grandma became the busiest person of the family. Grandma was a kind old lady. She was good at cooking. All her relatives liked the food she cooked. During “Fair time”, they would come to live in her house and have meals there. Grandma was always happy to look after them.

    Year after year, many people moved to big cities. There was no longer “Fairtime”. Grandma became very old and was gradually going blind. My parents and I moved to live with Grandma. We did our best to make her life comfortable. I was at high school then. What I often did at home was to help Grandma with the daily newspaper's crossword puzzle. However, she didn't look happy. She often sat in her room for hours, without saying a word.

    To attract(吸引) people to move back, the Town Hall decided to reopen the fair. One day, when I came back from school, I saw Grandma wearing her glasses, washing the dishes in the kitchen. With a big smile on her face, she looked much younger. She told me that her two nieces(侄女) would come. “They said the food I cooked was very delicious and they wanted to stay in my house again,” Grandma said happily. “They will stay here for one week and we can have a big party. That must be the busiest week I've had in years!”

    I suddenly realized that Grandma didn't want to be looked after. She wanted to be “useful” and helpful.

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