單項(xiàng)選擇題
A.變徑 B.三通 C.直通 D.四通
A.0.3 B.0.4 C.0.5 D.0.6
A.4 B.5 C.6 D.7
A.0.2m B.0.5m C.1m D.1.5m
A.5m B.10m C.15m D.20m
A.1.2m B.1.5m C.2m D.2.5m
A.0.001 B.0.002 C.0.03 D.0.003
A.0.8m B.0.9m C.1.0m D.1.2m
A.5 B.6 C.7 D.8