题干

下列叙述正确的是

A:促性腺激素释放激素、抗利尿激素只能作用于垂体细胞

B:过氧化氢酶通过为过氧化氢供能来提高化学反应速率

C:人突然受到寒冷刺激时;引起骨骼肌不自主的收缩而打寒颤,属于条件反射,该反射弧的神经中枢主要在下丘脑,而冷觉感觉中枢在大脑皮层

D:Na+具有维持细胞外液渗透压的重要作用,神经元受到刺激时它将内流

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D

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    Anaya Elick was born without hands – she has stubs(残端)where most people's wrists begin.

    To hold a pencil, she must balance it between her wrists, then use her arms to push it along the page. But that didn't stop her from winning a national handwriting contest when she was in first grade.

    In the two years since, she has taken on greater challenges. Last week, she won another national handwriting contest, this one for cursive(草书). And by all accounts from her teachers at Greenbrier Christian Academy, she has become an accomplished artist.

    Anaya isn't one to boast about her successes. She unwillingly says they make her proud but adds that they come from “lots of practice.”

    Her friends at school said, “She inspires everybody by what she does and how she does it” child to fail, and raising one who was born with a disability can heighten that protective instinct.

    Before Anaya was born, doctors knew about her condition, although not its cause. Other than having no hands, she is a regular 9-year-old girl.

    Anaya succeeds because she is not afraid to fail, Middleton said. The two began practicing cursive last year, when Anaya was in second grade. She struggled sometimes, because unlike traditional penmanship, which allows for breaks after each letter, cursive words are written straight through – and added effort for someone who must balance rather than hold the pencil.

    Middleton could see her daughter thinking through the challenge, figuring out how she could do better. She'd get frustrated at times, but she never hesitated to do things as often as it took to get them right.

    “I don't think I've ever heard Anaya say I can't do something,” Middleton said.

    That attitude carries over to her other interests.

    Recently, Anaya and her classmates sat in Cheryl Leader's art room, working on an exercise. The goal was to get them thinking about different concepts, like color combinations and how an image can be formed by fully coloring inside straight and diagonal lines.