When I was in high school our physics teacher gave us a challenge 【小题1】 involved making a paper airplane of any shape. The only objective was to get it to fly as far as possible. 【小题2】 (stand) at the starting line, one of my classmates took a piece of flat paper, crumpled (把……捏成一团) it up, and 【小题3】 (throw) it down the way. He beat the class with ease. Some of the students got mad and said that he cheated, but the physics teacher 【小题4】 (clear) explained it could be any shape and that a paper ball was indeed a shape.