A.截止閥 B.止回閥 C.旋塞閥 D.閘板閥
A.平齊處 B.以下10cm C.以下20cm D.以下30cm
A.3000 B.2000 C.1000 D.500
A.0.05%~0.1% B.0.1%~0.2% C.0.2%~0.5% D.1.0%~2.0%
A.C7H12 B.C7H16 C.C7H8 D.C7H14