It is known that after the concrete is adjusted by trial mixing, the amount of various materials is: cement 3.10kg, water 1.86kg, sand 6.24kg, crushed stone 12.8kg, and the apparent density of the mixture is 2500kg ∕ m3 . : (1)How much is the amount of per cube concrete material? (2)If the moisture content of sand at the construction site is 2.5%, and the moisture content of stone is 0.5%, find the construction mix ratio.