心电图显示V1导联QRS波群呈rsR
A．室间隔缺捌B．房间隔缺损C．动脉导管未闭D．肺动脉瓣狭窄E．法洛四联症
参考答案：B
—Excuse me, could you tell me __________?
—In ten minutes.
A．how long the train will leave
B．how soon the plane will arrive
C．when did the train leave
D．when the train left
PID控制器是控制系统中常用的（）。
A.有源校正装置
B.无源校正装置
C.前馈校正
D.反馈校正
