sand on the floor scrunched under our feet.
地板上的沙子在我们脚下嘎吱作响。
sand martin is a brown bird with white underneath.
崖沙燕是一种褐羽白腹的`鸟。
all walked barefoot across the damp sand to the water's edge.
他们全都光着脚走过潮湿的沙地来到水边。
ship has come to rest on the fine sand.
这艘船停靠在细沙滩上。
