单项选择题
A.8A B.9A C.10A D.11A
A.7V B.8V C.9V D.10V
A.2.5~3.55kPa/cm2 B.2.85~4.55kPa/cm2 C.3.75~6.5kPa/cm2 D.3.95~7.15kPa/cm2