The top curve shows the body weight of a genetically obese mouse that eats nonstop until it turns fat, like this furry tennis ball.  And the bottom curve is the weight of a normal mouse.
上面的曲线显示体重 是一个有肥胖基因的老鼠 不停的吃， 直至它变得象这个毛茸茸的网球一样胖。 下面这个曲线是正常老鼠的体重。