多项选择题 The basis of decline curve analysis is that future production continues to follow the past trend, we can use these models to estimate ( ).A.original gas in placeB.ultimate gas reservesC.remaining productive lifeD.formation permeabilityE.skin factor

单项选择题 超急排斥主要由下列哪种因素引起（）

单项选择题 RC正弦波振荡器可产生幅值连续可调和频率可调的正弦波。 A、正确 B、错误