题目内容
10.Do you have brown hair?Are you taller than other kids your age?These characteristics were decided before you were born.You got your traits from your parents.They passed their traits on to you through genes(基因).Genes carry codes (代码) for blue eyes or brown eyes.Genes say how tall you will get and what color hair you will have.You got half of your genes from your mother.You got half of your genes from your father.So you have your own set of genes.Each person gets different genes for each body part.That is why you look like but not exactly like your brother or sister.
A dominant (显性的) gene shows up most of the time.Brown eyes are dominant over blue eyes.A recessive (隐性的) gene shows up less often.Light hair comes from a recessive gene.Dark hair is more common.Look at the eye color and hair color of the people around you.You will see that this is true.
Genes help to make you who you are.But they don't tell the whole story.Your genes may help you to be fast and strong.But you still need to learn how to run or swim or skate well.
31.The underlined word"traits"in Paragraph 1 meansA.
A.charactcristics
B.expericnces
C.achievements
D.possibilities
32.According to Paragraph 3,you can see most of the people around you haveA.
A.brown eyes with dark hair
B.brown eyes with light hair
C.blue eyes with dark hair
D.blue eyes with light hair
33.What is the passage mainly about?B
A.Genes carry codes for eyes and hair.
B.Genes help to make you who you are.
C.Genes help you to be fast and strong.
D.Genes make brothers look similar.
分析 短文主要介绍了基因和性状之间的关系,作为一个人,有一半的基因来自父亲,有一半基因来自母亲,有的基因是显性的,有的是隐性的.
解答 答案:31.A 词义猜测题.根据下文"They passed their traits on to you through genes"父母的traits通过基因遗传给后代,我们知道,通过基因遗传的是性状,结合选项,所以traits应该是个性、显著的特点的意思,故选A.
32.A 细节推理题.根据第三段第一行句子"Brown eyes are dominant over blue eyes.Dark hair is more common"控制棕色眼睛性状的基因是显性基因,黑发更为普遍.可知由此我们可以知道众人中常见的性状是黑发,棕色的眼睛,故选A.
33.B 主旨归纳题.根据整篇文章内容及其最后一段句子"Genes help to make you who you are"基因使得你成为独一无二的,可知文章通篇都在介绍基因和性状之间的关系,故选B.
点评 在通读全文的基础上,根据全文大意,展开逻辑思维,瞻前顾后,认真观察选项,仔细推敲,确定最佳答案.
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