【英语时差8,16】咖啡渍的奥秘

 Next time you spill a little, let the coffee dry before wiping it up. You’ll notice that after it dries there is a darkish ring around the very edge of the spill, whereas the middle disappears almost entirely¹. What’s going on here? Robert Deegan and Sydney Nagel at the University of Chicago looked into this phenomenon, and they discovered something pretty interesting. The coffee puddle² leaves a ring because it doesn’t simply dry where it sits. As the spill begins to dry, it actually creates its own outward motion, drawing the insides of the puddle toward the edges.

1 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

2 puddle   

n.(雨)水坑，泥潭

参考例句：

• The boy hopped the mud puddle and ran down the walk.这个男孩跳过泥坑，沿着人行道跑了。
• She tripped over and landed in a puddle.她绊了一下，跌在水坑里。