three piece of后用名词的单数还是复数

后面跟不可数名词,所以也就没有复数形式
但piece 要变成复数,
如三张纸
three pieces of paper

扩展阅读：threesome in the office ... one day a book seller ... how old is your friend ... who is the girl in red ... how to keep healthy ... is your girl friend like ... three pieces of papers ... he was young then ... i repeated my question ...