? ?They know they are contributing very little of real value and all the time they live in fear of being exposed as cheats.?? ? 这里的 exposed 是过去分词。be exposed as ...的意思是“被暴露出 ......的真实面目”。例如：He was publicly exposed as a liar and a cheat. 他的说谎和骗子的面目被公诸于众。/ She has been exposed as a fraud. 她骗子的真实面目被暴露出来。（摘自《牛津英语搭配词典》英汉双解版，第2版p.625）