A.0.5≤η B.η≤0.8 C.η>1 D.0.5≤η≤0.8
A.3 B.1 C.2 D.4
A.4個(gè)晶閘管 B.4個(gè)二極管 C.2個(gè)晶閘管和2個(gè)二極管 D.2個(gè)晶閘管和2全個(gè)場(chǎng)效應(yīng)管