評(píng)論
打印
Recording 50
錄音50
You will hear a lecture about hair.
你將聽(tīng)到一段關(guān)于毛發(fā)的講課。
First, you have some time to look at questions 31 to 40.
首先，你有時(shí)間看看第三十一題至第四十題。
Now listen carefully and answer questions 31 to 40.
現(xiàn)在仔細(xì)聽(tīng)錄音，并回答第三十一題至第四十題。
Good morning, and welcome to this lecture on hair which is a part of the human biology course.
早上好，歡迎大家來(lái)上這節(jié)關(guān)于毛發(fā)的課，這是人體生物學(xué)課程的一部分。
This lecture covers a number of facts about hair: its structure and what can affect the general health of hair.
這節(jié)課將涵蓋關(guān)于頭發(fā)的好幾點(diǎn)知識(shí)：毛發(fā)的結(jié)構(gòu)，以及影響毛發(fā)整體健康的因素。
So, first of all, what is hair and why do we have it?
首先，什么是毛發(fā)，為什么要有毛發(fā)？
If we look back at our ancestors, we'll see that they had a lot more hair on their bodies than we do now.
如果我們追溯到我們的祖先那一代人，我們就會(huì)發(fā)現(xiàn)，他們的毛發(fā)比我們現(xiàn)在可多得多。
And there are (or were) two main reasons for having hair. One is to provide warmth... but as humans have worn clothes for many years, body hair has significantly reduced.
長(zhǎng)毛發(fā)主要有兩個(gè)原因，第一是供暖……但由于人類已有多年穿衣史，體毛就大大減少了。
The other is for protection. And again this isn't as significant as it was once, but hair does still benefit areas of the body such as the head and around the eyes.
另一個(gè)原因是提供防護(hù)。重申一次，其防護(hù)作用以遠(yuǎn)不如前，但毛發(fā)對(duì)身體某些部位而言還是很有益處的，比如頭部和眼周。
Now hair, whatever it is for and wherever it is on the human body, is composed mainly of a protein called keratin.
毛發(fā)，不論其用途和分布何處，其成分主要是一種叫角蛋白的蛋白質(zhì)。
This, by the way, is also found in fingernails. In fact, it's keratin which makes them flexible and without it they would be very rigid.
順便一提，角蛋白也存在于指甲中。實(shí)際上，正是角蛋白使毛發(fā)和指甲變得具有彈性，否則就會(huì)非常堅(jiān)硬。
Another interesting fact about hair is that it is very strong, as strong as iron in fact.
關(guān)于毛發(fā)的知識(shí)中，還有一點(diǎn)比較有趣的是，毛發(fā)非常強(qiáng)韌，實(shí)際上相當(dāng)于鐵的強(qiáng)度。
One single strand can support a weight of up to 100 grams.
單單一根毛發(fā)能承受至多100克的重量。
This may not sound all that much, but a full head of hair can support up to 12 tonnes, which is the equivalent of a couple of elephants, which is simply amazing, though I advise you not to put this to the test!
這聽(tīng)起來(lái)可能不太多，但一整頭頭發(fā)最高可承受12噸，相當(dāng)于兩只大象的重量，這可太令人驚訝了。當(dāng)然，我不建議你們?nèi)L試。
