A.5~10;管路相對較長 B.10~20;就地測點比較分散 C.20~30;管路相對較短 D.30~40;單獨一根儀表管
A.120~150mm B.70~100mm C.150~250mm D.100~150mm
A.abdc B.badc C.dabdc D.dbadc