A.7d B.15d C.30d D.90d
A.5min B.10min C.15min D.20min
A.局部服從整體 B.低壓電網(wǎng)服從髙壓電網(wǎng) C.下級(jí)電網(wǎng)服從上級(jí)電網(wǎng) D.優(yōu)先保護(hù)自有設(shè)備