A.陽(yáng)極電壓最高 B.陽(yáng)極電壓最低 C.陰極電壓最髙 D.陰極電壓最低
A.0.34U2 B.0.45U2 C.0.58U2 D.0.68U2
A.60° B.120° C.150° D.180°