带有稳压放大环节的稳压电源,其放大环节的放大倍数越大,输出电压越稳定。
参考答案:对
They __________ with each other for two years before they got married.
A.had fallen in love
B.got in love
C.had been in love
D.fell in love
下列哪种物质具有过敏毒素作用()。
A.C3a、C4a、C5a
B.C3b、C4b
C.C1~C9
D.C1q
E.C2b