时间:2018-12-24 作者:英语课 分类:Scientific American(三)月


英语课

This is Scientific American's 60-Seconds Science. I'm Karen Hopkin. This will just take a minute.


 


Elephants. They’re the SUVs of the animal kingdom. They’re big and rugged 1, and can carry lots of cargo 2. And now a study in the Proceedings 3 of the National Academy of Sciences suggests they come equipped with the quadruped version of all-wheel drive.


When it comes to locomotion 4, elephants are not exactly fleet of foot. And they seem to hold their legs straighter than other animals do, at least when they walk. So scientists set out to examine more closely how elephant limbs mechanically move all that mass around.


Six Asian elephants walked or ran over a sidewalk equipped with pressure sensors 5, as the scientists used high-speed video cameras to monitor their gait. And they found that elephant legs actually do bend enough to provide significant leverage 6 when on the move. More surprising is that pachyderms’ front and rear legs are on equal footing when it comes to acceleration 7 and braking. All other four-legged animals, like dogs or cats or horses, divvy up those duties. With their rear legs powering the push forward, and their front legs acting 8 as brakes.


That arrangement lets elephants trade speed for stability. Sadly, it does nothing for their fuel economy. Of course, they do have the roomiest trunk.


 


Thanks for the minute for Scientific American's 60-Seconds Science. I'm Karen Hopkin.

 



1 rugged
adj.高低不平的,粗糙的,粗壮的,强健的
  • Football players must be rugged.足球运动员必须健壮。
  • The Rocky Mountains have rugged mountains and roads.落基山脉有崇山峻岭和崎岖不平的道路。
2 cargo
n.(一只船或一架飞机运载的)货物
  • The ship has a cargo of about 200 ton.这条船大约有200吨的货物。
  • A lot of people discharged the cargo from a ship.许多人从船上卸下货物。
3 proceedings
n.进程,过程,议程;诉讼(程序);公报
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
4 locomotion
n.运动,移动
  • By land,air or sea,birds are masters of locomotion.无论是通过陆地,飞越空中还是穿过海洋,鸟应算是运动能手了。
  • Food sources also elicit oriented locomotion and recognition behavior patterns in most insects.食物源也引诱大多数昆虫定向迁移和识别行为。
5 sensors
n.传感器,灵敏元件( sensor的名词复数 )
  • There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
  • Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时,有很大变化。 来自辞典例句
6 leverage
n.力量,影响;杠杆作用,杠杆的力量
  • We'll have to use leverage to move this huge rock.我们不得不借助杠杆之力来移动这块巨石。
  • He failed in the project because he could gain no leverage. 因为他没有影响力,他的计划失败了。
7 acceleration
n.加速,加速度
  • All spacemen must be able to bear acceleration.所有太空人都应能承受加速度。
  • He has also called for an acceleration of political reforms.他同时呼吁加快政治改革的步伐。
8 acting
n.演戏,行为,假装;adj.代理的,临时的,演出用的
  • Ignore her,she's just acting.别理她,她只是假装的。
  • During the seventies,her acting career was in eclipse.在七十年代,她的表演生涯黯然失色。
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学英语单词
Aboriginals
accumulated earning tax
amors
anepithymia
antirecipocal circuit
apiose
army list, Army List
Autocompetition
batten ends
Bender Cassim
blows you off
boiling holes
cancerettes
cardiac dwarf
chained connection
chiang kan
choupori
chuuch
cleaning fan
Clinton County
cognitive development theory
conoce
cranlan
devisacope
directorate of standards
dredge
drive key
farmans
fine cargo
fore-lying
frequency primary standard
general nature
give free transportation of
homeyer
horseway
idle labor
in-situ soil test
incalculably
inland distribution depot
instantaneous total closure
intracapsular ligaments
isonomia
jurisprudentially
kordax (greece)
Kornilow's reflex
lacrimatories
lid spring
low voltage commutator
Madarao-yama
ministerial standard
monolithic photodiode
multiple virtual storage
nanopaper
nar nar
non-foaming oil
nonbarotropic
NSHS
on-line refuelling
one-year file
out-Herods
overmodulate
Pandion haliaetus
played with fire
political life
polyaoxylin
Posadasis spheriforme
pot limit
potentises
precast prestressed concrete
prefocation
professional dancer
protactinium(iv) oxide
protoplasma
Qin dynasty
record level
ReLC
resonant wire drawing force meter
Rhodininae
roadway
sequential testing
shahjahan
spheroidal weathering
spline surface
stock adjustment demand function
strut rod
sun-2 workstation
superpetrosal
superselling
telephone dials
tiruchchendur (tiruchendur)
toll line
transfunding
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uniform circular motion
us wrote
volumetric concentration
well-closed containet
westerfield
wolfram lamp
zotepine
zymogen