红苋菜细胞的液泡中含有呈紫红色的花青素。将红苋菜的叶片切成小块后放入水中,水的颜色无

题型:单项选择题

问题:

红苋菜细胞的液泡中含有呈紫红色的花青素。将红苋菜的叶片切成小块后放入水中,水的颜色无明显变化。若进行加热,随着水温升高,水的颜色逐渐变红。其原因是()

A.细胞壁在加温后受到破坏

B.水温升高,花青素的溶解度加大

C.加温使细胞膜和液泡膜失去了控制物质进出的功能

D.加温使花青素分子的活性加大而容易透过细胞膜

考点:高中生物细胞的结构与功能细胞的结构与功能题库
题型:单项选择题

C

Throughout the world, clothing has many uses. It is used to provide protection from the elements. It is also worn to prevent others from seeing specific parts of one's body. However, the parts of the body that must be covered vary widely throughout the world. Some clothing is worn to

provide supernatural protection. Wearing a lucky shirt to take an exam is calling for supernatural assistance.

People in all cultures use clothing and other forms of bodily decoration to communicate status,intentions and other messages. In North America, we dress differently for business and various leisure activities. North American women usually are much more knowledgeable of and concerned

With little difference in messages communicated by clothes than men. At times, this leads to silly mistakes of interpretation(解释) of female intentions on the part of men. Of course. clothing styles also are intended to communicate messages to members of the same gender(性别).

Long before we are near enouth to talk to someone, their appearance tells their gender, age,economic class. and often even intentions. We begin to recognize the important cultural clues at an early age. The vocabulary of dress that we learn includes not only items of clothing but also

hairstyles, jewelry, and other body decoration. In most cultures, however, the same style of dress communicates different messages depending on the age, gender. and physical appearance of the individual wearing it.

Putting on certain types of clothing can change your behavior and the behavior of others towards you. This can be the case with a doctor's white lab coat, or an army uniform. Most uniforms are clearly symbolic so that they can rapidly and unmistakably communicate status. For instance. the

strange hairstyle and clothing of the English "punks" are essential aspects of their uniforms.

There are many forms of body decoration other than clothes that are used around the world to send messages. These include body and hair paint, and even body deformation. When doctors put braces on teeth, they are actually doing the same thing - deforming or reforming a part of the body

to make it more attractive.

49. What is the passage mainly about?

A. Clothing and Culture          B. Communication through Clothing

C. Clothing and Social Behavior  D. Ways of Sending Messages

50. In North America men sometimes misunderstand women's intention because

A. men are more careless than women

B. women spend more time on their clothes

C. men and women have different views on clothing styles

D. men care less about the different messages communicated by clothes

51. From the passage. it can be inferred that__________

A. messages communicated by clothes are the same in different cultures

B. words of dress are not enough to communicate different messages

C. dress is better than language in communicating messages

D. clothing plays an important role in social activities

52. What does the underlined word "essential" mean in this passage?

A. beautiful       B. necessary      C. unimportant     D. Common

题型:单项选择题

化脓性中耳炎耳源性颅内、外并发症最常见的侵犯传播途径包括()。

A.血行途径

B.循破坏、缺损的骨壁

C.正常的解剖途径

D.尚未闭合的骨缝

E.淋巴途径

题型:单项选择题

斜井提升具有设备简单、投资少、见效快等优点。

题型:单项选择题

执行如下程序,输出星号(*)的个数为
#include<iostream>
using namespaee std;
class Sample
public:
Sample( )
~Sample( )cout<<’*’;

int main( )
Sample temp[2],*pTemp[2];
return 0;

A.1

B.2

C.3

D.4

题型:单项选择题

某市政府采取“一企一策”的办法推动“僵尸企业”问题的解决。对符合破产条件的企业及时引入破产程序,对兼并重组后可以重生的企业促其兼并重组,对无意愿无能力继续生产的企业依法收回用地,盘活存量土地,从而促进了该市经济的快速发展。上述材料表明()

①政府主要通过行政手段处置僵尸企业

②破产有利于淘汰落后企业

③破产和兼并有助于压缩企业规模

④兼并可以提高企业和整个社会的资源利用效率

A、①②

B、①③

C、③④

D、②④

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