题干

科研人员对某草原一种野生动物的种群进行研究,得出了与种群密度相关的出生率和死亡率的变化,如图5所示c有关叙述正确的是(   )

A:该生物的种群增长曲线呈“J'型

B:死亡率增加的原因是食物、空间和天敌等因素

C:要合理利用该种动物资源,应将种群密度控制在D点

D:B点时,种群增长速率最大,种群达到最大环境容纳量

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B

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    One day, I took an underground to work, I saw something that made me very sad. On the tube (underground in London), a mother kept looking at her phone screen and playing a game with her daughter sitting beside her. The little girl, about 5 years old, was talking to her mother about herday, repeating the next stop's name cheerfully, praising her mother's long nails—trying to draw her mother's attention. Her mother just nodded and mumbled "Mm, hm" with her eyes glued to the screen, busy passing the levels of the game. I watched the girl give a final try to at least get her mum to look at her, but it was no use. Then the little girl turned silent. It was a shame the mother didn't notice that.

    It broke my heart and got me wondering—what kind of game would make the mother forget she has the most beautiful thing in the world, the human she created, the person she loves with all her heart? What it meant when she couldn't look into her daughter's eyes and even stop to listen to the girl?

    Some parents are almost like the teenagers, always on their phones with mindless games or going through Facebook. Perhaps parents have many things to deal with, but sometimes they are everything to their kids.

    This is not an isolated example. I've seen too many such examples. I might not be a parent myself, and probably still have a long way before becoming one, but I know what I saw isn't right.

    The scene used to be seen among teenagers very often when parents complained how their children were crazy about their mobile phones. Look how the situation has changed! The parents have become "technology slaves", that is to say, they can't control themselves while using mobile phones.  Now some middle-aged parents hold the best iPhones or Samsung phones, which are probably the only two brands they know. They are playing the simple games with so expensive mobile phones. I'm uncertain whether to laugh or to cry. But my hope is that this storm passes.