艺术与物理的共同主题是（    ）
A、时间
B、空间
C、光
D、人物
E、事件
F、质量
G、未来

A.Ⅰ.Ⅱ
B.Ⅰ、Ⅲ
C.Ⅰ、Ⅳ
D.Ⅰ、Ⅱ、Ⅳ

A．The diode is not good enough.
B．We cannot put all the amplified signal into the on-state of the diode.
C．The current-controlled-current-source is expensive
D．The diode is with exponential u-i relationship.