男女羞羞视频在线观看,国产精品黄色免费,麻豆91在线视频,美女被羞羞免费软件下载,国产的一级片,亚洲熟色妇,天天操夜夜摸,一区二区三区在线电影
首 頁 | 新聞英語 | 視聽英語 | 翻譯園地 | 實用英語 | 專欄作家 | 奧運英語 | 新詞新譯 | 書友天地 | 輕松英語  | 凈臉聯盟 | 英語論壇 | 少兒英語
您現在的位置: En_language tips > 輕松英語 > 一問到底 Dec 26, 2005
 





  Why does hair turn gray?

   
  Gray hair
   
  Why does hair turn gray?
Hair goes gray because pigment cells in the hair base at the roots of the hair stop producing melanin.

It doesn't matter if you are fair-haired or dark-haired you have the same chances of getting gray hair. However, it is more noticeable in darker haired people.

Graying of the hair generally starts at the age of around 30 for males and 35 for females however since the onset of this phenomena varies greatly from person to person, age is not the most accurate indicator.

The graying of hair appears to be genetically determined but the connection isn't at all clear.

So for now, your hair turning gray is just one of those mysteries of science that we have yet to solve. But salt and pepper hair always did look distinguished.

 

note:

pigment: 色素
melanin: 黒色素

 

 

 

onset: 開始

 

 



salt and pepper: 黑白相間而呈灰色的

 
 
 
Copyright by chinadaily.com.cn. All rights reserved
版權聲明:未經中國日報網站許可,任何人不得復制本欄目內容。如需轉載請與本網站聯系。
None of this material may be used for any commercial or public use. Reproduction in whole or in part without permission is prohibited.
主站蜘蛛池模板: 龙里县| 泸水县| 望都县| 吐鲁番市| 白山市| 娄烦县| 外汇| 广饶县| 漠河县| 康马县| 沙坪坝区| 池州市| 泾阳县| 建平县| 金堂县| 吴忠市| 南郑县| 阿拉尔市| 任丘市| 廊坊市| 台北市| 贵港市| 永新县| 蓝田县| 桐乡市| 海原县| 钟山县| 昌吉市| 临猗县| 德格县| 河东区| 丹巴县| 高陵县| 化德县| 昆山市| 雷波县| 眉山市| 九龙城区| 榆中县| 青岛市| 京山县| 始兴县| 来安县| 宜君县| 汝城县| 马边| 界首市| 石嘴山市| 临朐县| 新干县| 吴忠市| 武功县| 开封县| 岑溪市| 克拉玛依市| 广安市| 华池县| 志丹县| 尉氏县| 抚顺县| 浦城县| 三河市| 彭阳县| 泌阳县| 汾阳市| 天门市| 七台河市| 海丰县| 尼玛县| 嵊州市| 七台河市| 东兰县| 红安县| 北票市| 汝阳县| 仙游县| 江永县| 赣榆县| 荔浦县| 额济纳旗| 乐业县| 天水市|