1. clothes, cloth, clothing clothes统指各种衣服，谓语动词永远是复数， cloth指布，为不可数名词 clothing 服装的总称，指一件衣服用a piece of, an article of 2. incident, accident incident指小事件, accident指不幸的事故He was killed in the accident. 3. amount, number amount后接不可数名词， number后接可数名词 a number of students
