A.30s B.40s C.50s D.60s
A.油泵的吸人壓力 B.油泵的排出壓力和吸人壓力之差 C.冷水泵的排出壓力 D.冷水泵的排出壓力和吸入壓力之差
A.高于調(diào)定值 B.低于調(diào)定值 C.高于或等于調(diào)定值 D.低于或等于調(diào)定值