【英语时差8,16】网球场
时间：2018-12-27 作者：英语课 分类：英语时差8，16
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.
- 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！
- 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。
- 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。