日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

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: 国产成人综合精品 | 色婷婷久久久亚洲一区二区三区 | 手机免费看毛片 | 亚洲一区欧美二区 | 国产黄频在线观看 | 免费视频国产 | 啪啪毛片 | 天天摸夜夜操 | 国产网友自拍 | 国产福利一区二区三区 | 欧美激情免费视频 | 亚洲成人一区在线 | 手机免费黄色网址 | 粉嫩av绯色av蜜乳av | 自拍中文字幕 | 极品闺蜜苏姨小说阅读 | 国产女18毛片多18精品 | 自拍亚洲色图 | 国产三级三级在线观看 | 精彩久久 | 色综合天天综合网国产成人网 | 日韩午夜激情 | 午夜爽爽视频 | 91a视频| 伊人夜夜 | 五十路av| 亚洲免费在线观看 | 69xx免费视频 | 欧美色综合网 | 欧美一级全黄 | 成人毛片在线精品国产 | 亚洲成人www| 奶波霸巨乳一二三区乳 | 麻豆视频91 | 嫩草影院污 | 超碰超碰超碰超碰 | √8天堂资源地址中文在线 亚洲成人黄色片 | 日日日日日 | 超碰免费观看 | 青青艹在线观看 | 黑人操亚洲女人 |