单项选择题
A.1.5~2 B.2~3 C.3~3.5 D.3.5~4
A.50% B.60% C.80% D.100%
A.高支架敷设 B.浅埋暗挖敷设 C.盾构敷设 D.架空敷设
A.内径不大于400mm B.外径不大于400mm C.内径不大于500mm D.外径不大于500mm
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