单项选择题
A.0到-30kpa B.-30到-50kpa C.-50到-80kpa D.-30到-80kpa
A.0.10-0.15mpa B.0.15-0.20mpa C.0.20-0.25mpa D.0.25-0.30mpa
A.0.3-0.4mpa B.0.4-0.5mpa C.0.5-0.6mpa D.0.7-1.0mpa