A.壓力在4.0MPa,液位70%以上 B.壓力在3.0MPa,液位50%左右 C.壓力在4.0MPa,液位50%左右 D.壓力在3.0MPa,液位70%以上
A.2 B.5 C.8 D.18
A.30% B.50% C.70% D.90%