VOA慢速英语:美国特勤局实验室研究墨水以解决犯罪问题

ink – n. colored liquid that is used for writing or printing

sample(s) – n. a small amount of something that gives you information about the thing it was taken from

library – n. a place where books, magazines, and other materials (such as videos and musical recordings) are available for people to use or borrow

branch – n. a major part of a government

counterfeit – adj. made to look like an exact copy of something in order to trick people

bag – n. a container made of thin material (such as paper, plastic, or cloth) that opens at the top and is used for holding or carrying things

gentleman – n. a man who treats other people in a proper and polite way

intellect – n. the ability to think in a logical way

proud(er) – adj. very happy and pleased because of something you have done, something you own, or someone you know or are related to