The parcel was full of stones and sand!请问：sand是可数的,为什么没用sand

The parcel was full of stones and sand!请问：sand是可数的,为什么没用sand The precious parcel was full of stones and sand中 full of OF指 someone had filled the parcel with stones and sand有人在装满了石头和沙 with lots of sand sand是可数还是不可数 请问 “share of sand” The basket was full of sand after the fisherman drew it out sand 可数吗? a thick layer of sand and a thin layer of tiny stones succes sand到底是可数还是不可数的啊 The boy draws on the sand ____thin sticks or stones. wind and sand A Grain Of Sand