单项选择题
A.178:293:792:1139:2.93 B.220:367:792:1140:3.67 C.176:293:792:1139:2.93 D.178:367:790:1139:3.67
A.≥1700kg/m3 B.≥1800kg/m3 C.≥1900kg/m3 D.≥2000kg/m3
A.不低于160mm B.100mm~150mm C.160mm~200mm D.150mm~1850mm