A.10.5kV,40.5kV,121kV,252kVB.10.5kV,40.5kV,126kV,230kVC.12kV,37.5kV,121kV,230kVD.12kV,40.5kV,126kV,252kV
A.長(zhǎng),小,不需要B.長(zhǎng),大,不需要C.短,小,需要D.短,大,不需要
A.3B.4C.1D.2