建筑抗震设计应符合的要求有( )。Ⅰ.应符合概念设计的要求；Ⅱ，当采用严重不规则的方案时，应进行弹塑性时程分析；Ⅲ.不应采用严重不规则的设计方案；Ⅳ，当采用严重不规则的方案时，应作振动台模型试验

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.