staple
/ˈsteɪpl; `stepl/ n
1 small thin piece of bent wire that is driven into sheets of paper, etc and flattened to fasten them together 订书钉.
2 U-shaped piece of metal with pointed ends that is hammered into wood, etc to hold something (eg an electrical wire) in place U 形钉（如固定电线用的）. staple, v [Tn]
attach or secure (sth) with a staple or staples 用订书钉或 U 形钉钉住或固定（某物）.
staple / ˈsteɪpl; `stepl/ adj [attrib 作定语]
main or principal; standard 主要的; 基本的; 标准的
the staple product of a country 一个国家的主要产品
Rice is the staple diet in many Asian countries. 稻米是亚洲许多国家的主食.
She seems to be the staple topic of conversation at the moment. 看来她是此时的热门话题. staple, n (often pl 常作复数)
1 main product that a country or district trades in （某国家或地区买卖的）主要产品
Cotton is one of Egypt's staples. 棉花是埃及的主要贸易项目之一.
2 main or principal item or element (esp of a diet) 主要成分; 主要内容; （尤指）主食
Bread, potatoes and other staples continue to rise in price. 面包、 土豆及其他主食的价格继续上涨.
The weather forms the staple of their conversation. 天气状况是他们的主要话题.