staple可以作名词和动词。但作名词时该词是可数名词。
（1）a small piece of thin wire that is pushed into sheets of paper and bent over to hold them together订书钉
（2）a small U-shaped piece of metal with pointed ends， used to hold something in place U型钉
（3）a food that is needed and used all the time基本食物，主食
例如：staples like flour and rice
面粉和大米等主食
（4）the main product that is produced in a country一国的主要产品
例如：Bananas and sugar are the stables of Jamaica.
香蕉和糖是牙买加的主要产品。
