A.10m B.20m C.30m D.40m
A.L1A.、L2B.、L3C.、N、PE B.L1A.、N、L2B.、L3C.、PE C.L1A.、L2B.、N、L3C.、PE D.PE、L1A.、L2B.、L3C.、N
A.4Ω B.10Ω C.30Ω D.100Ω