desk是不是可数名词

　　I always leave a clear desk at the end of the day.

　　每天工作结束时，我总是把桌上收拾干净不放任何东西。

　　The paper had fallen down between the desk and the wall.

　　那张纸掉在桌子和墙壁之间的缝隙里。

　　That desk takes up too much space.

　　那张桌子占的地方太大。