单项选择题
A.2 B.3 C.4 D.5
A.10cm B.15cm C.20cm D.25cm
A.5cm B.10cm C.15cm D.20cm
A.5.0mm B.2.5mm C.4.75mm D.2.36mm
A.20±1℃ B.20±2℃ C.20±3℃ D.20±5℃
A.10% B.15% C.20% D.25%
A.1：3，1.0 B.1：4，0.5 C.1：3，0.5 D.1：4，1.0
A.50N/s±10N/s B.100N/s±10N/s C.2500N/s±200N/s D.2400N/s±200N/s
A.5mm B.10mm C.15mm D.20mm
A.10kg/m3 B.20kg/m3 C.30kg/m3 D.40kg/m3
A.0.7~1.1 B.0.75~1.15 C.0.8~1.2 D.0.85~1.25