mindmap root((同意屈尊帮助拯救大众)) bulk implies an aggregate that is impressively large, heavy, or numerous: the darkened ~s of skyscrapers towered over him. （aggregate总数 mass suggests an aggregate made by piling together things of the same kind: the cave held a ~ of pottery. volume applies to an aggregate without shape or outline and capable of flowing or fluctuating: a tremendous ~ of water.