把水泥、黄沙、石子按2:3:5配制成混凝土,石子占混凝土的请选择ABC8m,^8e(]6|'s4j(`5L6B/W2k)X7r+E2d8z2P
A.2/54j(`5L6B/W2k)X7r+E2d8z2P
B.3/54j(`5L6B/W2k)X7r+E2d8z2P
C.1/24j(`5L6B/W2k)X7r+E2d8z2P