A、8~30s B、9~10s C、8~20s D、9~30s
A、3.0~3.5MPa B、2.65~2.84MPa C、2.5~3.5MPa D、2.75~3.12MPa
A、0.3kPa B、0.3kPa C、0.5kPa D、0.6kPa