A.主极T1为正,T2为负;门级电压G为正,T2为负B.主极T1为负,T2为正;门级电压G为正,T2为负C.主极T1为正,T2为负;门级电压G为负,T2为正D.主极T1为负,T2为正;门级电压G为负,T2为正
A.I+和III+B.I-和III-C.I+和III-D.I-和III+