摘要：鉛筆是我們生活中十分常見的物品,常見到我們甚至很少會注意到它。其實,小小鉛筆的背后有著不少故事,看完這篇文章之后,你或許會對它'另眼相看'。On March 30,1858,inventor Hymen L.Lipman patented the first pencil with a built-in eraser—then sold it for$100,000.