题目内容
Does stress cause gray hair? Many people believe that tension and stress can cause your hair to lose its color．In fact，it is an old wives tale that being upset all the time can result in premature graying．Here is a closer look at this situation and why some believe that this old wives tale could be true．
As one ages，the hairs on the head also age．In fact，just about everything on the human body begins to show signs of wear and tear after a while．The joints wear and become stiff and skin wears and becomes wrinkled．Hairs on the head grow and eventually die．They are replaced，but in the process something else happens．
When new hairs are replaced，the color or pigment(色素)is also added to them．However，as one ages，this pigment becomes less and less available．At first，hairs will have a limited amount of pigment and they will appear to be grayish in color．In time，they will lose all of their pigment and will be white．Many things are known to cause graying．and genetics is a very powerful factor．If one of your parents turns gray at an early age，there is a good chance that you will too．Some people begin the graying process in high school，while others may be over the age of forty．
Constant worry and tension can have many harmful effects on the human body．It is a known fact that stressful times can cause one to suffer hair loss．It would make sense that if it can cause these problems，perhaps it also may contribute to graying．However，there is no sound evidence to support this．
On the other hand，many medical professionals believe that there may be a link：between graying and a constant state of anxiety or tension．Does stress cause gray hair? There is no scientific evidence to support the theory，but it is best to avoid stressful situations．
1.The underlined phrase in the first paragraph most probably means .
A．clever remarks B．silly remarks
C．exciting remarks D．disappointed remarks
2.The second paragraph mainly tells us .
A．every part of body is replaced with age
B．hairs will grow weak but not die
C．skin becomes wrinkled with age
D．every part of body ages with age
3.From the passage we can infer that .
A．stress causing gray hair is still in question
B．gray hair has nothing to do with tension．
C．stressful situations can be of benefit．
D．sound evidence has been found．
4.What might play the most important role in the graying process?
A．Genetics and the amount of sleeping time
B．The amount of food people eat and living environment
C．The amount of pigment and genetics
D．Genetics and the amount of water people drink
1.B
2.D
3.A
4.C
【解析】
试题分析：压力会导致头发变白吗？很多人相信情况是这样的。本文从年龄和基因两方面谈论了头发变白的原因，持续的压力和忧虑对身体是有害的，可导致脱发。但究竟压力和头发变白之间是否有联系，目前尚无科学的证据。
1. 词义猜测题。根据本段的第二句“Many people believe that tension and stress can cause your hair to lose its color．”可知许多人认为紧张和压力会导致头发褪色变白。文章接下来谈到“In fact，it is...”以及下文可知，这种论断是没有科学依据的，故an old wives tale 是指不经之谈或不科学的陈腐思想，选B。
2. 主旨大意题。根据第二段的第一句和第二句“As one ages，the hairs on the head also age．”“In fact，just about everything on the human body begins to show signs of wear and tear after a while．”可知，人体的每一部分都会随着年龄的增长而衰老。D项恰当地概括了该段的大意，故选D。
3. 推理判断题。倒数第二段的最后提到“However，there is no sound evidence to support this．
”以及最后一段提到“There is no scientific evidence to support the theory...”，由此可知，压力是否会引起头发变白尚无定论。故选A。
4. 细节理解题。根据第三段的第三、四、五句“At first，hairs will have a limited amount of pigment and they will appear to be grayish in color．In time，they will lose all of their pigment and will be white．Many things are known to cause graying．and genetics is a very powerful factor．”可知，色素和基因在头发变白的过程中起着重要的作用。故选C。
考点：考查科学常识类短文阅读
Many people believe they are supposed to drink eight glasses of water a day, or about two liters. Why? Because that is the amount of water they have been told all their life. But a recent report offers some different advice. Experts suggest people should obey their bodies: they should drink as much water as they feel like drinking.
The report says most healthy people meet their daily needs for liquid by letting thirst be their guide. The report is from the Institute of Medicine, which provides scientific and technical advice to the government and the public. The report contains some general suggestions. It says women should get about 2.7 liters of water daily and men about 3.7 liters. But wait–in each case, that is more than eight glasses.
There is one important difference. The report does not tell people how many glasses of water are needed to meet these guidelines. This is because the daily water requirement can include the water content in foods.
As you might expect, the Institute of Medicine says people need to drink more water when they are physically active. The same is true of those who live in hot climates. Depending on heat and activity, people could need twice as much water as others do.
All this, however, does not answer one question. No one seems sure why people have the idea that good health requires eight glasses of water daily. It may have started with a misunderstanding.
How much water we should drink every day
Belief or advice | the 1.________ of water needed daily | |||
Traditional public belief | men | eight glasses of water | women | 2.________ glasses of water |
A 3.________ medical report | men | 4.________ than 3 liters of water | women | 2.7 liters of water |
while doing hard 5._______ or in the hot 6.________ | ||||
men | 7.4 liters of water | women | 7.________ liters of water | |
Experts’ 8.________ | as 9.________ as our bodies need, 10.________ the water from other foods | |||