Did you know that a person has around 5 million hair follicles1 all over thebody？ We all have hair. It’s a natural part of the human body. Do you eversometimes wonder2 why we have it？ Here are some facts about it.

你知道一個(gè)人全身大約有500 萬個(gè)毛囊嗎？我們都有毛發(fā)，這是人體的自然組成部分。你何曾想過為什么我們會(huì)有它呢？以下是一些和毛發(fā)相關(guān)的趣聞。

1 We have 100，000 hairs.

我們有10 萬根頭發(fā)遙

Did you know that a person can have around 100，000 hairs？ Not only this butwe also have up to 150，000 hair follicles just on our head and around 5 million allover our body. You are born with some number of follicles on your body and youdon’t grow more as you get older.

你知道一個(gè)人可以有大約10 萬根頭發(fā)嗎？不僅如此，我們頭上還有多達(dá)15萬個(gè)毛囊，全身大約有500 萬個(gè)。你出生時(shí)身體上就有一些毛囊，隨著年齡的增長，你不會(huì)再長出更多毛囊。

The number of follicles you have is hereditary3 and can change depending4 onyour hair color. People with naturally blonde hair have more follicles which are about150，000 hairs on their head， while people born with naturally red hair have onlyaround 90，000 follicles.

你的毛囊數(shù)量是遺傳的，會(huì)根據(jù)發(fā)色而改變。天生金發(fā)的人有更多的毛囊，大約有150，000 個(gè)，而天生紅發(fā)的人只有大約90，000 個(gè)毛囊。

2 Information5 can be stored6 in our hair！

信息可以儲(chǔ)存在我們的頭發(fā)里

As our hair grows it carries our bodies’information with it. We cannot see theinformation just by eyes， but there are ways of testing that help us to see the changesmade to a piece of hair when it grows. For example， we can see from one’s hair ifthere was a lack of vitamins and nutrients at a point of time in the diet.

隨著頭發(fā)的生長，它攜帶著我們身體的信息。我們不能只靠眼睛看來獲取信息，而是有一些測(cè)試方法可以幫助我們看到一根頭發(fā)在生長過程中的變化。例如，我們可以從一個(gè)人的頭發(fā)看出在某個(gè)時(shí)間點(diǎn)的飲食中是否缺乏維生素和營養(yǎng)。

3 Human hair is both stretchy7 and strong.

人類的毛發(fā)很強(qiáng)韌

Human hair is so strong that it could hold more weight8 than a piece of copperwire9. It is said that a whole head of hair could carry the weight of around 5，600 to8，400 kilograms， or the weight of two elephants.

人類的頭發(fā)非常結(jié)實(shí)，與一根銅絲相比它能承受更多的重量。據(jù)說一個(gè)人全部的頭發(fā)可以承載大約5600 到8400 公斤的重量，這相當(dāng)于兩頭大象的重量。

Human hair is also very stretchy. If you have curly hair， you can stretch10 it outuntil it becomes straight， but everyone’s hair stretches at some point. Dry hair canstretch to be around 1.2-1.3 times as long as before and it can return back. Whenour hair is wet， it can stretch even more， sometimes up to 1.5 times.

人類的頭發(fā)也很有韌性。如果你有一頭卷發(fā)，你可以把它拉長，直到它變直，但是每個(gè)人的頭發(fā)在某種情況下都可以拉長。干燥的頭發(fā)可以拉伸到原來的1.2到1.3 倍，并且可以恢復(fù)到原來的長度。當(dāng)我們的頭發(fā)打濕之后，它可以拉得更長，有時(shí)可以達(dá)到1.5 倍。

4 What is the growth11 cycle12 of a follicle？

毛囊的生長周期是怎樣的

The first step is the growth of a hair. Once the hair is fully grown， it hasstopped growing but stays in the follicle until it is ready to fall out. A hair can livefor around 5 years before it falls out.

第一步是長出頭發(fā)。一旦頭發(fā)完全長出來了，它就會(huì)停止生長，但會(huì)留在毛囊中直到它快要脫落。一根毛發(fā)可以存活5 年左右才脫落。

Although the number of follicles stays the same all your life， as you get olderyour hair can naturally fall out. This means you will have less hair on your head orbody but the follicles are still there. Then the follicle willlose the hair. A person loses between 50-100 piecesof hair a day.

雖然人一生中毛囊的數(shù)量保持不變，但隨著年齡的增長，頭發(fā)會(huì)自然脫落。這意味著你頭上或身體上的毛發(fā)會(huì)變少，但是毛囊還在。之后毛囊就會(huì)掉毛。一個(gè)人每天會(huì)掉50 到100 根頭發(fā)。

5 Temperature13 can work on hair growth.

溫度會(huì)影響頭發(fā)的生長

Does temperature work on hair growth？ It is said that warmer climates14 makeyour hair grow faster. In some studies this could be true， but it is not enough tomake it a fact. We do know that colder climates can work on your hair. Cold aircan make your hair dry because there is a lack of humidity15 in the air. This cancause split16 ends as the hair becomes brittle17.

溫度對(duì)頭發(fā)生長有影響嗎？據(jù)說溫暖的氣候會(huì)讓你的頭發(fā)長得更快。在一些研究中，這可能是真的，但這不足以使其成為事實(shí)。我們知道寒冷的氣候會(huì)對(duì)你的頭發(fā)產(chǎn)生影響。冷空氣會(huì)使你的頭發(fā)干燥，因?yàn)榭諝庵袧穸炔蛔恪ｋS著頭發(fā)變得脆弱起來，發(fā)梢就會(huì)分叉。

Hair is an important part of human body. We canuse it to do some tests about our bodies; it keeps us warmin cold climates and is part of our identity18.

頭發(fā)是人體的重要組成部分。我們可以用它來做一些關(guān)于我們身體的測(cè)試；它讓我們?cè)诤涞臍夂蛑斜３譁嘏?，也與我們自身特性相關(guān)。

▏Notes

1. follicle （皮膚上的）毛囊

2. wonder 想知道，好奇

3. hereditary （特點(diǎn)或疾病）遺傳的

4. depend 取決于

5. information 信息，資料；知識(shí)

6. store 貯存，儲(chǔ)藏

7. stretchy 有彈性的；能伸展的

8. weight 重量

9. copper wire 銅線

10. stretch （使）變大，拉長

11. growth 成長，生長

12. cycle 周期

13. temperature 溫度，氣溫

14. climate 氣候

15. humidity 潮濕，濕氣；濕度

16. split 分裂，使分裂

17. brittle 易碎的，脆的

18. identity 身份，特性