国产热热热精品,亚洲视频久久】日韩,三级婷婷在线久久,99人妻精品视频,精品九热人人肉肉在线,AV东京热一区二区,91po在线视频观看,久久激情宗合,青青草黄色手机视频

首 頁(yè) | 新聞?dòng)⒄Z(yǔ) | 視聽(tīng)英語(yǔ) | 翻譯園地 | 實(shí)用英語(yǔ) | 專欄作家 | 奧運(yùn)英語(yǔ) | 新詞新譯 | 書(shū)友天地 | 輕松英語(yǔ)  | 凈臉聯(lián)盟 | 英語(yǔ)論壇 | 少兒英語(yǔ)
您現(xiàn)在的位置: En_language tips > 輕松英語(yǔ) > 一問(wèn)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(kāi)始

 

 



salt and pepper: 黑白相間而呈灰色的

 
 
 
Copyright by chinadaily.com.cn. All rights reserved
版權(quán)聲明:未經(jīng)中國(guó)日?qǐng)?bào)網(wǎng)站許可,任何人不得復(fù)制本欄目?jī)?nèi)容。如需轉(zhuǎn)載請(qǐng)與本網(wǎng)站聯(lián)系。
None of this material may be used for any commercial or public use. Reproduction in whole or in part without permission is prohibited.
永兴县| 钦州市| 遂川县| 天台县| 教育| 永兴县| 曲周县| 隆安县| 洮南市| 金川县| 化德县| 竹山县| 图木舒克市| 额敏县| 义乌市| 元谋县| 建德市| 石棉县| 内丘县| 西峡县| 富源县| 恭城| 浙江省| 淮阳县| 阿坝县| 黄龙县| 鄂尔多斯市| 太康县| 北海市| 金昌市| 精河县| 荃湾区| 汾阳市| 金山区| 姜堰市| 奉贤区| 新建县| 茌平县| 新郑市| 定陶县| 遂川县|