I know that half of ____ I spend _____ is wasted.

A．that; to advertising

B．what; to advertise

C．what; on advertising

D．what ; on advertise

NPN晶体三极管放大状态其电流关系（）

A、IB=IC+IE

B、IE=IC+IB

C、IC=IB+IE

D、IC=IB×IE