The wall is white.
墙是白的,“墙”在这里作为整体,看多单数,.
wall是可数的
n.[C]
1.墙,壁;围墙;城墙
2.墙状物;障壁
3.(容器等的)壁,内壁
The walls of the furnace are under repair.
炉壁正在修理.