锯齿波触发电路中双窄脉冲产生环节可在一个周期内发出间隔（）的两个窄脉冲

A.60°

B.90°

C.180°

D.120°

A.60°

B.90°

C.180°

D.120°

A.矩形波产生与移相

B.脉冲形成与放大

C.尖脉冲产生与移相

D.三角波产生与移相

A.单宽脉冲

B.间隔为120°的双脉冲

C.间隔为60°的双窄脉冲

D.单窄脉冲

E.大于60°的脉冲列

A.60°

B.90°

C.120°

D.180°

A.60°

B.90°

C.120°

D.180°

A.60°

B.120°

C.90°

D.180°