he saw a penny on the ground.He picked it up and happily put it into his pocket.The penny was his,and it cost him nothing 最后这个为什么是nothing
问题描述：
he saw a penny on the ground.He picked it up and happily put it into his pocket.The penny was his,and it cost him nothing 最后这个为什么是nothing
答
他什么都没花,钱就是他的了.