电子电路中直流偏置电压随输入信号幅度而变化的，称为自给（）。
参考答案：偏压
胃气钡双重造影时，显示胃小区大小为直径约（）
A.0.5～1mm
B.0.5～2mm
C.1～3mm
D.2～4mm
E.3～5mm
No one appreciated his work during his lifetime, but________it is clear that he was a great artist.
A．in the aftermath
B．by the time
C．in retrospect
D．in this eventuality
