2016高考英语二轮阅读理解一百六十集选练（39）

　　阅读理解

　　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.

【2016届高考英语二轮复习阅读理解一百四十集选练：（39）】相关文章：

★ 2014届高考英语一轮复习课时作业(十九)必修4Module 1《Life in the Future》（外研版）

★ 2014届高考英语一轮复习必修4参考答案（外研版）

★ 四川省广安市2014高考英语一轮基础训练题（5）及答案

★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (65)

★ 【浙江专用】2014届高考英语一轮复习课时作业(二十六)选修6Unit 1《Art》

★ 2017届高考英语二轮复习课时训练：18（含解析）

★ 四川省2016届高考英语一轮复习课时作业（37） Module 1 Basketball 外研版选修8

★ 四川省广安市2014高考英语一轮基础训练题（3）及答案

★ 【人教版】2014届高考英语一轮复习指导考点针对练：必修1 unit3《Travel journal》

★ 【北京专用】2014届高考英语一轮复习方案课时作业：必修2 Unit 1 Cultural relics