A.防潮 B.防堿 C.防腐 D.防酸
A.2h+b=550~600mm B.2b+h=550~620mm C.2h+b=600~620mm D.2b+h=620~650mm
A.可松性系數(shù) B.密實(shí)系數(shù) C.壓縮率 D.堅硬系數(shù)