piano river table可数嘛 哪个可数哪个不可数?

piano river table可数嘛 哪个可数哪个不可数? river可数吗? table lamp可数么 river,matter,community可数不可数 violin,piano可数吗?如果可数,为什么只说playing the violin,playing the piano呢? piano 什么意思嘛 ball是可数还是不可数?还有table tennis club是可数还是不可数? 复数形式 goose,tooth,sheep,mouse,table,potato,piano,loaf,glass,weather. There is a big_____and_____nice food on the table.David is ______the piano. Just now he played _____ table tennis and I played _____ piano. 请问在英语中,江河湖海是可数名词吗?即river lake sea ocean 是可数名词吗? River River river “River river ( ) ( )( )( ) ( )( ) River river