A.5m B.10m C.15m D.20m
A.設在低處敷設 B.設在中間處敷設 C.應在高處敷設 D.無要求
A.0.01~0.1兆帕 B.0.1~0.15兆帕 C.0.2~0.7兆帕 D.1~2兆帕