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问题 单项选择题

对转基因生物的安全性问题，人们在哪些方面存在着争论（）

①转基因生物可能存在食物安全问题

②很多被转移的基因是异种基因

③转基因生物可能影响到环境安全

④科学家对基因的结构、基因间的相互作用以及基因的调控机制等都了解得相当有限

⑤转基因生物可能存在生物安全问题

A.①②④

B.①③⑤

C.③④⑤

D.②③④

答案

参考答案：B

阅读理解

Almost every child is scared of something, from monsters in the cupboard to dogs in the park. But the fact that such fears are common and normal doesn’t mean they can be taken lightly. Kids experience fears and phobias (恐惧症) much more strongly than adults. And the influence of the fear can be physical as well as psychological (心理的). It can build up so they almost seem scared of everything-a kind of childhood anxiety. Dr. Creswell says:"Your child may always seem to expect the worst to happen and lack confidence in his or her ability to deal with any challenge.” So don’t make the same old mistake of treating them as if they’re silly for being “a scared cat”（胆小鬼）. Handing the fears is essential.

Children can be born nervous and., if you have such a baby, you’ll tend to prevent them from getting worried. So if they fear dogs, you’ll keep them away from dogs, but in fact that can just confirm to the child that dogs are scary. What is worse, keeping your child away from what they fear can turn that feeling into a phobia. Instead, you should encourage them to get in touch with the thing they fear, in a safe and supportive environment. Dr. Andy Field, a researcher of childhood fears, says: “You shouldn’t force, for example, a dog anxious child to go up to a dog. But you can approach it yourself, show them there is nothing to be afraid of, stroke (抚摸) it, and talk about the dog being friendly. Once your child dares to stroke a dog-one that’s good with children, of course-then you should encourage them to carry on until they feel calmer, and reward them for ‘being brave’.”

小题1:Children’s fears are usually taken lightly because     .

A．they will not develop into phobias

B．their influence is psychological

C．they exist widely in the world

D．they will disappear gradually小题2:If we fail to help children to overcome fears, they will    .

A．make the same old mistake

B．overcome them by themselves

C．experience the worst of things

D．grow up lacking self-confidence小题3:According to Dr. Andy Field, if a child is afraid of a cat, parents should     .

A．tell the child not to be afraid of it

B．show the child how to approach it

C．keep the child away from it

D．ask the child to stroke it
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单项选择题

阅读下文。回答下列题：
有这样一种假说，冬眠是一种高度发达的机能。冬眠的哺乳动物虽然与人类一样都是温血动物，但是它们在更宽范围的调节性上获得了进化，例如在体温调节上，就要比非冬眠动物强。
传统认为，哺乳动物冬眠的奥秘在于心脏。无论冬眠动物，还是非冬眠动物，甚至人类，其心脏的工作原理是相同的。当钙离子流进心脏的细胞时，就引起心脏收缩；当他排出细胞时，心脏又开始舒张。但是随着温度的降低，非冬眠动物的心脏细胞排出钙离子的能力明显降低，从而使心脏的舒张越来越困难，最后导致死亡；而此时冬眠动物的心脏细胞则完全与此相反。因此心脏细胞调节钙离子浓度的机制，是冬眠时心脏正常活动的关键所在。
后来的研究证实，心脏细胞的这种变化还不是冬眠的根本原因，科学家们推测冬眠最终是由动物体内的遗传基因控制的。然而，人们却一直没有发现这种基因，直到最近日本科学家发现，在美洲松鼠等冬眠动物的血液中，存在一种特殊的蛋白质HP。HP只能在冬眠动物身上找到，并与冬眠同步出现，这表明他在冬眠中具有重要作用。
那么，在人类身上也能找到类似冬眠的现象吗人类也可能冬眠吗答案是肯定的。人在睡眠时也有体温降低，心跳放慢的现象，这在性质上与冬眠相似。而身体硕大的熊冬眠，为实现人类的冬眠提供了可能。如果以HP为线索，也许能重新认识熊冬眠。一旦控制熊冬眠的遗传基因得以破译，人的冬眠就不是不可能了，这样，人类就能把自身的代谢控制到最低极限，从而有利于癌症等疾病的长期治疗，未来的宇宙旅行等。

本文第一段提出一种假说，对这种假说理解不正确的是：

A．在物种进化的过程中，某些哺乳动物在调节上获得了进化，从而具备了冬眠的功能

B．比较起人类来，冬眠的哺乳动物在更宽的范围里发生了进化

C．冬眠的哺乳动物比起人类来，具有更强的体温调节机制

D．冬眠的哺乳动物和非冬眠的哺乳动物之间的区别，并不在于体温是否可以调节
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