It was ___ he said ___ disappointed me.
A.what; that
B.that; what
C.that; when
D.it; when
答案:A
心室的易损期在()。
A.QRS波末到ST段开始后20ms
B.T波升至顶峰之前约30ms
C.P波初始20ms
D.P-R间期内
E.P波初始10ms
1140V供电系统中,为保证电动机的端电压不低于额定电压值的95%,则供电网线路所允许的电压损失为()