给你一支吸管,一支普通的用来喝牛奶的吸管;再给你一只土豆,一只刚从菜场买来的拳头大的土豆。请问,你能用吸管穿透土豆吗?不能!——大概你会这样说。那么,再给你一个辅助工具——杯子,情况又会怎么样呢?就让我们亲自动手试一试吧。先将土豆架在杯子上,接着用右手的四指抓紧吸管,再用拇指扣紧吸管的顶端,最后 Give you a straw, an ordinary straw to drink milk; give you a potato, a big fist bought from the farms. Excuse me, can you penetrate potatoes with a straw? No! - Probably you would say that. Well, give you a complementary tool - the cup, the situation will happen? Let us try it yourself. First potatoes in the cup rack, then grabbed the right four fingers straw, and then use the thumb to fasten the top of the straw, and finally