單項選擇題
A.8 B.10 C.15 D.20
A.60kV B.50kV C.35kV D.30kV
A.70kV B.60kV C.50kV D.40kV
A.不 B.直接 C.經(jīng)消弧線圈 D.間接
多項選擇題
A.10% B.15% C.20% D.25%