A.50 B.40 C.30 D.20
A.200W B.220W C.500W D.550W
A.這兩個(gè)節(jié)點(diǎn)的電位都高 B.這兩個(gè)節(jié)點(diǎn)的電位一定大于零 C.這兩個(gè)節(jié)點(diǎn)的電位都低 D.這兩個(gè)節(jié)點(diǎn)的電位差大