A.10% B.30% C.50% D.100%
A.稳压 B.稳流 C.防高电压反击 D.抗干扰 E.保证不间断供电
A.升高 B.不变 C.降低
A.越小越好 B.越大越好 C.<10% D.>10%
A.1/2 B.1/3 C.2/3 D.3/4