A.用電量大 B.負(fù)荷密度高 C.對安全可靠要求高 D.對供電質(zhì)量要求高
A.8%~12% B.10%~15% C.12%~17% D.15%~20%
A.+7%~-10% B.±7% C.±10% D.-7%~+10%