单项选择题
A.30m B.55m C.80m D.120m
A.kg B.h C.m D.dB
A.结合层、面层、承重层、顶棚 B.结合层、承重层、顶棚、面层 C.面层、结合层、承重层、顶棚 D.基层、结合层、承重层、顶棚