Since then I        a member of the family and never        from them.

A．have be come; will I separate

B．have be come; I will separate

C．have been; will be separated

D．have been; I was separated

如图所示，将一圆筒开口向下缓慢压入恒温水池中，将筒中空气视为理想气体，则在圆筒缓慢下降过程中（　　）

A．筒内空气的压强在增大

B．筒内空气的温度在升高

C．筒内空气向外界放热

D．筒内空气的内能减小