paper可数吗,paper什么意思

急急急英语50个不可数名词和50个可数名词.食物类
pieces of paper a bag of rice ------ three bags of rice 三,可数
a piece of meat/paper/bread/music/ination/furniture/machinery
kindle paperwhite 4 值得买吗?
鱼肉(不可数) glass—玻璃杯(可数); 玻璃(不可数) paper—试卷