Fat free
油是免费的

I stopped at a fast food restaurant recently. I was fascinated by a sign which offered Fat Free French Fries. I decided to give them a try. I was dismayed when the clerk pulled a basket of fries from the fryer which were dripping with fat. He filled a bag with these fries and put them in my order. "Just a minute!" I said. 'Those aren't fat free." "Yes, they are. We only charge for the potatoes.... The fat is free!"

有一次我走进一家快餐店，被一个标志牌吸引了，上面写着“无油薯条”。我打算尝尝，但是看到服务员从锅里捞出的一篮薯条沾满了油，真是吓了我一大跳。他给我装了一袋，账单上显示出价钱。“等会儿，”我说，“这不是无油的？”“是的，我们只对薯条收费，油是免费的！”