单项选择题
A.50Pa (2inH2O)B.100Pa(2inH2O)C.150Pa(2inH2O)D.500Pa(2inH2O)
A.YJ27型接装机B.YJ29A型接装机C.YJ212型接装机D.AF12型接装机
A.过紧B.过松C.滤嘴接装过牢D.滤嘴直径过大