A sheet of paper.paper用的是单数,如果Two sheets of paper.这个paper也用单

A sheet of paper.paper用的是单数,如果Two sheets of paper.这个paper也用单 a double sheet of paper. a separate sheet of paper的意思 a double sheet of paper怎么理解 a sheet of paper和a piece of paper的区别? 是a piece of paper 还是 a slice of paper two kinks of paper ...谓语动词用单数还是复数? a piece of paper 请问:a piece of paper和a sheet of paper有区别吗? we,that is,the two sides of a sheet of paper,how can we sepa a piece of paper可以用a paper吗?为什么? PAPER