The Human Body: Life Story 生命物语-12

But if I were to tell you just the science of these changes I would be missing the most important thing of all. Let me show you what I mean.

This is the amount of tears that an average person cries during a lifetime. Just a fraction under 65 liters, or to put it another way, about 1 million 850 thousand drops. So what do you know about them? Well, each tear weighs 35, 000 th of a gram and is about as salty as this part of the River Thames, at Greenwich.

Tears are produced by a gland¹ just above the eye which is literally² squeezed when we cry and the tears come down 6 tiny tubes about the thinness of a human hair. As far as we can tell, of all the animals in the world only humans actually cry when we are hurt or upset, about 28 drops each time. Though they are 99% water, tears also contain around 80 other ingredients, including sugar and antiseptics.

But what's the most important thing to know if all these were your tears, of course, it's why you cried them. How many of these thousands of droplets³ were shed in fits of anger? How many in pain, how many in love, in grief, how many in sorrow, how many were shed by a baby and how many by an old man facing the end of life? The truth is, a knowledge of the science of life is only made complete by a knowledge of those living it. The human body is not just a biological machine. It's much more than that. It's a person.

And in this series, it's people that will tell us what the body's ever changing story really means. Take Zach for example， having already mastered the complexities⁴ of crawling, he will be taking his first steps.

words and expressions

antiseptic: A substance that inhibits⁵ the growth and reproduction of disease-causing microorganisms.
抗菌剂：抑制致病微生物生长和繁殖的物质

in fits of :（感情的）激发
in a fit of rage
一时气愤

1 gland   

n.腺体，(机)密封压盖，填料盖

参考例句：

• This is a snake's poison gland.这就是蛇的毒腺。
• Her mother has an underactive adrenal gland.她的母亲肾上腺机能不全。

2 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

3 droplets   

n.小滴( droplet的名词复数 )

参考例句：

• Droplets of sweat were welling up on his forehead. 他额头上冒出了滴滴汗珠。 来自辞典例句
• In constrast, exhaled smoke contains relatively large water droplets and appears white. 相反，从人嘴里呼出的烟则包含相当大的水滴，所以呈白色。 来自辞典例句

4 complexities   

复杂性(complexity的名词复数)； 复杂的事物

参考例句：

• The complexities of life bothered him. 生活的复杂使他困惑。
• The complexities of life bothered me. 生活的杂乱事儿使我心烦。

5 inhibits   

阻止，抑制( inhibit的第三人称单数 )； 使拘束，使尴尬

参考例句：

• A small manufacturing sector inhibits growth in the economy. 制造业规模太小有碍经济增长。
• His bad English inhibits him from speaking freely. 他英语学得不好，这使他不能表达自如。