时间:2018-12-27 作者:英语课 分类:英语时差8,16


英语课

Some people prefer clay tennis courts, others like grass. Yael and Don discuss the difference on this Moment of Science. Y: Hey Don, what do you say to a game of tennis later? D: Sure thing, Yael. But it has to be a clay court, okay? Y: But the grass courts are so close by. Why clay? D: I prefer clay because I'm able to slide in more easily for a shot, not to mention that the ball moves slower. Y: Why is that? D: Clay courts are covered with a layer of fine sand. This sand is slippery 1 enough for a player's shoes to slide around, but not so slippery that he or she is likely to slip and fall. This has to do with the shape of the sand. If it were perfectly 2 spherical 3, players would be slipping out of control. The sand on clay courts, however, has pointy bits with rounded ends. This same sand, though it allows the player to mover faster,slows down the motion 4 of the ball. This is because the cloth of the tennis ball captures 5 and drags sand as it hits the court. Y: If clay courts are so much easier to play on, then why do professional tennis players even use them? Wouldn't they want more of a challenge? D: It's not so much that one is easier than another. It really depends on the player. And good players know to adjust their serves according to the surface they're playing on. If it's grass, they serve as fast as possible. If it's clay they slow down the serve in order to put more spin on the ball. Both serves are difficult to return.



1 slippery
adj.滑的;油滑的,狡猾的,不可靠的
  • We found it very slippery under foot.我们感到地上很滑。
  • Mind out,the steps are slippery!注意,台阶很滑!
2 perfectly
adv.完美地,无可非议地,彻底地
  • The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
  • Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。
3 spherical
adj.球形的;球面的
  • The Earth is a nearly spherical planet.地球是一个近似球体的行星。
  • Many engineers shy away from spherical projection methods.许多工程师对球面投影法有畏难情绪。
4 motion
n.打手势,示意,移动,动作,提议,大便;v.运动,向...打手势,示意
  • She could feel the rolling motion of the ship under her feet.她能感觉到脚下船在晃动。
  • Don't open the door while the train is in motion.列车运行时,请勿打开车门。
5 captures
俘获( capture的第三人称单数 ); 夺取; 夺得; 引起(注意、想像、兴趣)
  • King Arthur himself captures the beast and cuts off its head. 亚瑟王亲自捉住怪物,并砍下它的头。
  • His book captures exactly the ethos of Elizabethan England. 他的书准确地描绘了英国伊丽莎白时代的风土人情。
学英语单词
Abies excelsa Poiret
ability of manager
adjustment after reconciliation
aggradation
aircraft electrical system
alternaria violae galloway et dorsett
apicycline
basic Q factor
bell rock (inchcape rock)
benzol
berwin
biafrans
biological spaceprobe
Birkenzell
boutons
Carnian Stage
catabatic winds
caudal medullary rest
cavity respiratory
chisellike
choristoderes
chronic constrictive pericarditis
Cockburn Town
coefficient of stability
coffin-maker
combustion liner
congenital auricular cyst
contact assembly
cooling passage
Cutato
dantz
darwin's theory of evolution
declaration under open policy
direct irritation
displeasure
downsizes
electronic impulser
elliptic paraboloid of revolution
ether-chloroform
eutroboralf
family carangidaes
findia
fixed-width fonts
flux rating
fuel changing
galling of rings
genus Hydrocharis
glass level cut
glycosphingolipidosis
goods bought in replacement
hadron multiplet
hericide
hibben
high moisture grains
histrionizing
Hnausar
Hydrocodin
immersion angle
landing zone of emergency rescue
Liceida
low temperature camera
menehune
metonymize
microphone response
microspectrophotometers
mudima
naticks
non-buyer
normal anomaly
online-retail
ordinary differential operator
ore harbour
overhead copying camera
overload time relay
pot-lid
pot-limit
prinovolva pudica
propellant evaporation
propellant transfusing room
propeller motor
resistant exercise
resolution line
rotary molding
schooltimes
sealing cone
ship to air net
single-voltage rating
small austere airfield
soldering bar
stope pillar
sural nerve
tighty
truncation of convolutional code
Tylostypia sven-hedini Kr.
typical cell
urbanized
virtute officii
Wakamiya-jiima
weatherized
Wilforzine
wooden-boat
X-ray powder pattern