已知函数f（x）=x²﹣2ax+a在区间（1，3）内有极小值，则函数g（x）= 在区间（1，+∝）上一定（  ）

      

下图为环境、资源和人口关系示意图，有关图中甲、乙、丙、丁含义的叙述，正确的是（    ）

读图填空题

读《三国鼎立形势图》，结合所学知识回答问题：

阅读下列短文，从每题所给的四个选项（A、B、C和D）中选出最佳选项。
      When an animal helps another animal，it usually gets something valuable in return. For a long time，many scientists thought that only people could act generously just because it feels good.
      However，a new study in Germany suggests that chimpanzees (an animal like a large monkey without a tail ) also do good things for no real reason. And so do children who are as young as 18 months of age. Maybe it is because humans and chimpanzees share an ancestor about 6million years ago.
      People and chimpanzees appear to develop such features without any other training，says Warneken，a scientist in Germany.
      Warneken and his partners worked on adult chimpanzees that live on an island in the African country of Uganda. They also worked with 18-month-old children in Germany. The researchers performed three experiments on the adult chimpanzees and two experiments on the kids. In the first animal experiment，a person tried to reach his arm into a cage to get a stick，but he couldn't reach it. A chimpanzee was in the cage，and it could reach the stick if it wanted to.
      Thirty-six chimpanzees took part in this experiment one by one，and no chimpanzee saw what the other chimpanzees had done. Even though the animals hadn’t met the person before，they usually took the stick and gave it to the person. What's more，they did this whether or not the person offered them bananas as a reward.
      In a similar experiment，36 children acted in a similar way. They helped the person reach the stick，whether or not they were offered toys for their help.
      Researchers did other experiments on chimpanzees and babies. No rewards were offered in either experiment. And still，both the chimpanzees and children went out of their way to help. Still，the new study is different from earlier findings. Researchers have found that chimpanzees don't give rewards of food to other chimpanzees，even if it costs them nothing to be generous.

二氧化碳的捕捉、封存与再利用是实现温室气体减排的重要途径之一。