人的大拇指能否向手背方向弯曲是由特定的遗传物质决定的,这个遗传物质是() A.所有的

题型:单项选择题

问题:

人的大拇指能否向手背方向弯曲是由特定的遗传物质决定的,这个遗传物质是()

A.所有的染色体

B.某一个基因

C.一个细胞核

D.全部的DNA

考点:显微镜知识竞赛显微镜知识竞赛题库
题型:单项选择题

为调查某地幼儿园1~6岁儿童生长发育情况设计一个调查表。项目有被调查者的姓名、出生年月、性别、身高、体重和血红蛋白值等内容。

此调查表中的哪一个项目的答案设计最适合用封闭式

A.血红蛋白值

B.体重

C.身高

D.性别

E.出生年月

题型:单项选择题

There I saw ten children________, two of whom were from 3.

A.in all

B.at all

C.all in all

D.above all

题型:单项选择题

There are many commonly held beliefs about eyeglasses and eyesight that are not proved facts. For example, some people believe that wearing glasses too soon weaken the eyes. But there is nothing to show that the structure (结构) of eyes is changed by wearing galsses at a young age. Wearing the wrong galsses, however, can prove harmful. Studies show that only children can develop loss of sihgt if they have the wrong glasses. We have all heard some of the common myths(荒诞的说法)about how eyesight get bad. Too little light makes the eyes work harder, so they do get tired and strained (过劳). Eyestrain also resulsts from reading a lot, reading in bed, and watching too much television. But, although eyestrain may cause some pain or headaches, it does not harm eyesight all the time. Another myth about eyes is that they can be replaced from one person to another . It is quite difficult to connect aneyeball to a new brain.And it is impossible to replace a whole eyeball to a new person. Only certain parts of the eye can be replaced now. But if we keep clearing up the myths and learning more about the eyes, some day it may be possible to replace a full eyeball.

小题1:

One cause of eyestrain mentioned in the passage is ____.        .

A.wearing eyeglasses too long

B.going to the cinemas

C.reading a lot

D.not visiting your eye doctor小题2:

.From this passage one can conclude that    ____.   .

A.doctors are still learning things about eyesight

B.headcaches are usually caused by eyestain

C.people should wear glasses as soon as possible

D.people only believe things that are proved facts小题3:

"Commonly held beliefs" are ____.       .

A.ideas that only low class people believe

B.ideas that moet people believe

C.beliefs that have something in common

D.foolish beliefs小题4:

This passage mainly tells us that ____.

A.people have many wrong beliefs about eyes and sight.

B.there are many things about the body that are not completely understood

C.there are several cuases of eyestrain

D.eyes are very important to people

题型:单项选择题

在龋病流行病学的集体备课时,王教授指出研究生甲对年龄因素的提法有一处是不对的

A.5~7岁乳牙患龋达高峰

B.9岁以后乳牙患龋率下降

C.恒牙萌出即可患龋

D.30岁左右恒牙龋达高峰

E.老年人根面龋发病率上升

题型:单项选择题

佛山是岭南水乡,遍布2800多条河涌,但其中大部分存在不同程度的污染。

上世纪80年代初大多数河涌仍能保持清澈,但随着污水排放增多,河涌的生态平衡遭到破坏,这说明()是有限的。

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