题干

下图是种群数量特征的概念模型,以下分析正确的是(  )

A:种群的密度能够反映种群的数量变化趋势

B:春节前后,郑州市的人口数量变化主要取决于①、②

C:预测未来种群数量变化的主要依据是④

D:利用人工合成的性引诱剂诱杀某种害虫的雄性个体来控制特征④,进而影响种群数量

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答案(点此获取答案解析)

C

同类题2

根据短文理解,选择正确答案。

    On the first day of school our teacher introduced himself and challenged us to get to know someone we didn't already know. I stood up to look around when a gentle hand touched my shoulder.

    I turned around to find a little old lady with a warm smile. She said, “Hi, handsome. My name is Rose. I'm eighty-seven years old.”

    “Why are you in university at such a YOUNG age?” I asked. She replied, “I'm here to meet a rich husband, get married, have a couple of kids, and then retire and travel.”

    I knew she was joking. I was curious what might have encouraged her to be taking on this challenge at her age.

    “I always dreamed of having a university education and now I'm getting one!” she told me. We became friends. Every day we would talk nonstop after class. I always enjoyed listening to this “time machine” as she shared her wisdom and experience with me. And Rose easily made friends wherever she went.

    At the end of the term we invited Rose to make a little speech. She cleared her throat(喉咙) and began, “We do not stop playing because we are old; we grow old because we stop playing. I've learned a few secrets to staying young, being happy, and achieving success. You have to laugh and find humor every day. You've got to have a dream. When you lose your dreams, you die.”

    “There is a huge difference between growing older and growing up. Anybody can grow older. That doesn't take any talent or ability. The idea is to grow up by always finding the opportunity(机会) in change...”