A.主梯為0,副梯為0 B.主梯為1,副梯為0 C.主梯為0,副梯為1 D.主梯為1,副梯為1
A.10cm B.5cm C.3cm D.0.5cm
A.40歐姆 B.60歐姆 C.120歐姆 D.180歐姆