【视频讲解】
Peacocks strut; bowerbirds build lovenests; spiders gift-wrap flies in silk. Such courtship rituals play an important role in what Charles Darwin called sexual selection: when the female of a species bears most of the costs of reproduction, males use extravagant displays and gifts to demonstrate their “reproductive fitness” and females choose between them.
孔雀开屏，园丁鸟筑巢，蜘蛛用蛛丝把苍蝇作为礼物包起来。上述动物求偶仪式在达尔文的性选择理论中举足轻重。性选择理论中说：当雌性动物承受了繁衍下一代的大部分代价时，雄性们则会用精美绝伦的表演和礼物来表明自己是适合交配的，从而让雌性从中做出选择。

peacock n.孔雀
strut v.趾高气扬地走
bowerbird n. 园丁鸟
lovenest n.爱巢
gift-wrap v.包装礼物
- wrap v.包裹住
courtship n.求爱
- court v. 追求，拍马屁
ritual n.仪式
bear v. 承担，忍受 (to accept or endure something)
- I can't bear seeing you cry.
reproduction n.繁殖，生育
- reproductive adj.繁殖的
extravagant adj.奢华的耀眼的 (fancy)
- We are going on a less extravagant vacation this year.

For human males, shards of a crystalline form of carbon often feature. A diamond engagement ring signals a man’s taste, wealth and commitment, all to persuade a woman that he is a good bet.
对于男人们来说，碳晶体碎粒往往是他们求爱的重头戏。一枚钻戒透露出的是一个男人的品味、财富和承诺，进而使女人相信他就一个好选择。

shard n.碎片 (a sharp piece of something)
- shards of
crystalline adj.结晶的
carbon n.碳
- carbon dioxide二氧化碳
feature v.扮演主要角色
signal v.预兆
commitment n.承诺
bet n.赌注，选择 (a choice made by thinking about what will probably happen)
- This is your best bet.

This particular courtship gift was dreamed up by an ad agency for De Beers, the cartel that sold almost all of the world’s diamonds throughout the 20th century. In the 1930s it started to promote a link between diamonds and marriage. Diamonds’ unmatched hardness would symbolise love’s endurance and their “fire”, or brilliance, its passion. Two months’ salary, the firm suggested, was what the ring should cost—a good investment since, as the admen said, “A diamond is forever.”

“求婚就要给钻戒”的观念最初是由一家为戴•比尔斯集团（De Beers）服务的广告公司编出来的。戴•比尔斯集团是钻石行业的卡特尔，该集团几乎垄断供应了上个世纪全球所有的钻石。在上世纪30年代，该集团开始做宣传，将钻石与婚姻联系在一起。钻石那无与伦比的硬度象征着爱情的持久，而钻石的“火光”或亮光象征着爱情的热烈。该集团当时称，两个月的工资就能买到一枚钻戒，配上广告中的宣传语 “钻石恒久远，一颗永流传”。这样算起来钻石还是一份不错的投资。
dream up 想出
De Beers 戴比尔斯（钻戒品牌）
cartel n.卡特尔，垄断组织
throughout prep.在...期间
promote v.宣传
unmatched adj.无与伦比的
endurance n.持久
- endure v. 忍受，接受，持久
- He endured great pain.
- The style endured for centuries.
admen n.广告人