三级aa视频在线观看-三级国产-三级国产精品一区二区-三级国产三级在线-三级国产在线

您現在的位置: Language Tips> Easy English> Odd Question  
 





 
鹿角為什么會脫落
[ 2007-07-16 17:37 ]

在動物世界中,鹿是唯一能再生完整的身體零部件的哺乳動物。當鹿角長到最大尺寸后,骨頭開始變硬,像天鵝絨一樣柔軟的鹿茸開始脫落。一旦鹿茸掉光,就剩下赤裸的骨頭,就可成為角斗中的強大武器。在交配期結束時,鹿角脫落以保存能量,等到春天來臨,在其頭頂上就能長出一對新的隆起的組織骨結節。

Deer shed their antlers annually as apreludeto the regeneration, or re-growth, of new ones.

The entire shedding process takes a mere two to three weeks to complete, and the re-growth phase takes place over the summer. Thedocilemale deer that, with the exception of the male and the female reindeer, solelysportsantlers, sheds them between January and April, after the autumnmatingseasondraws to a close. He can do without antlers at this time, because his need for them in prior months, to attract and to impress females for hisharemof mates, and to fight with his competitors for the females' affections, no longer exists.

The antlers themselves differ from the hollow horns of cattle, in that they comprise solid bone tissue with a honey combed structure.Pedicles, orknobby, skin-coverednubsprotruding from the skull, support the deer's antlers, or points, which range in number from one shaft to eleven branches. The pedicles are a permanent fixture on the deer's forehead, and are the point from which the antlers annually break off.

During the first year the pedicles appear on the young deer's forehead. The following year, the youngster sprouts straight, spike-like shafts, and in the third year, the first branch appears. In successive years, as the deer matures, his antlers lengthen and, in most species, he acquires additional branches. One can actually determine the age of the deer from the number of branches on his antlers, as their number increases with age.

During the growth phase of the bony antlers, they are covered with a sensitive skin referred to as "velvet", which is filled with blood vessels that feed the antlers the vitamins and the minerals necessary to build up the bone, and to promote normal antler growth. Antler growth spans two to four months, after which time the velvet is no longer needed, and a ring, which effectively serves as a shutoff valve, forms at the base of the antlers and cuts off the blood supply to the velvet. As a result, the velvet withers, dries up, and falls off, often assisted by the deer, which rubs his antlers against tree bark. The antler regeneration is complete, and the shedding cycle will resume once mating season in the fall concludes.

prelude: 前奏
docile: 溫順的
sport
: 炫耀,賣弄
mating: 交配
draw to a close: 漸近結束
harem: 一群雌動物
pedicle: 肉莖
knobby: 多節的
nub: 小塊
velvet: 天鵝絨

(來源:coolquiz.com 英語點津 Annabel 編輯)

我想了解更多趣味百科知識

 
 
相關文章 Related Stories
 
         
 
 
 
 
 
         
 
 

48小時內最熱門

     
  女孩的心思誰能猜:Suspended from class
  各種各樣的“錢”
  “搶鏡頭”怎么說
  姚明婚后打算:備戰奧運第一

本頻道最新推薦

     
  為什么畢業時要穿學位服
  We cats can use chopsticks, too!
  不受歡迎的夜半歌聲:打鼾
  US Independence Day(美國國慶日)
  Exercise after dinner

論壇熱貼

     
  “低生育,素質好,男女都是寶”,怎么譯為好?請教高手!
  請問“老鄉”這個詞怎么翻譯?
  C-E: how to say "路盲"?
  各位,“相親”英語怎么說?
  指紋上的ridges and loops是什么意思?
  請教一下 餃子的“餡” 用English怎么說啊






主站蜘蛛池模板: 一级做a爰视频免费观看2019 | 国产亚洲精品片a77777 | 国产乱码亚洲精品一区二区 | 日韩欧美一区二区三区视频 | 亚洲 欧美 精品 中文第三 | 大尺度做爰床戏呻吟免费观 | 国产香蕉国产精品偷在线观看 | 可以看黄色的网址 | 欧美一级毛片做受 | 免费成人黄色网址 | 欧美黄色录像 | 最新亚洲国产有精品 | 成人自拍视频网 | 黄色片xxxx | 玖玖爱在线观看视频在线 | 毛片xxxx| 欧美一级毛片高清免费观看 | 高清一级做a爱免费视 | 伊人色综合久久天天爱 | 中文字幕无线码中文字幕网站 | 91香蕉福利一区二区三区 | 成年女人毛片免费视频 | 千百橹最新亚洲地址在线播放 | 99国产国人青青视频在线观看 | 久久久99精品久久久 | 国产一级特黄aa级特黄裸毛片 | 拍拍拍无挡视频免费全程1000 | 尤物视频在线观看网址 | 欧美性野久久久久久久久 | 免费黄色片网址 | 亚洲第一成年免费网站 | 国产成人精品一区二区视频 | 美女一区二区在线观看 | 黄色大全片 | 亚洲精品99久久久久久欧美版 | 欧美成人艳星在线播放 | 欧美日韩在线成人看片a | 国产露脸对白91精品 | 人妖欧美一区二区三区四区 | 日韩中文字幕久久精品 | 南京巨根无套操到你窒息 |