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
acid-test ratio
ahigh
arc suppressing coil
as crooked as a dog's hind leg
asswhore
automatic stabilizer
avoiding chord
azzones
ballsbridge
Bergatreute
biocapacity
bleached paddy soil
buckling criteria
Cimanuk, Sungai
closed grating
coefficient of utilization of useful capacity
colloidal fuel
colpeurynter introducing forceps
commodity producer
conductive band
convolation
cordons sanitaires
cross sell
dessicator
dicky-seat
Dmitrovsk-Orlovskiy
dominant laterality
double squirrelcage motor
ecological system
elevator apron
epimera
erysipelas gangraenosum
eschewal
Football's a game of two halves
forfending
formula plan
froben
genus limnobiums
glucoscilliphaeoside
Hall's anchor
hip line
homer a. thompsons
hydraulic-machinery
ignition-switch
input-output interface system
instantaneous center/centre of rotation
intrumental
isothymol
keyboard input
klepto
liver coccidiosis
log well
maritime law institute
mass-energy
mincer and bowl cutter
mode of transducer
Montils
multiethnic education
no-claim
nonresponses
one-hundred-dollar
passive infrared rangefinder
pedaling
permissible limit of vibration
personal contact
phospholipidomics
Photinia chingiana
phylum chaetognathas
Piggott
pinnatifid
posumbu
prosperoes
pseudotriton ruber
pyramid method of hull construction
pyrenophora japonica ito et kuribayashi
Ranella
reaming bit
rhyacophila formosana
ringal
screen house
searls
Semple treatment
sexidentate ligand
Sheykino
silicon impregnation
Soltvadkert
spermatorrheas
subspectra
syndesm-
Thal Des.
thixotropic hardening
thorup
three-membered
twin tail
two-track recorder
vacuum-gauge
Vallen
very low frequency band radiated field system
Vila da Maganja
vision signal
Wairio
wind measuring device