画出三相变压器一、二次绕组Y,d1接线组别图及电压的相量图。
参考答案:
正常二尖瓣口面积为()。
A.1~2cm2
B.2~3cm2
C.3~5cm2
D.4~6cm2
E.6~8cm2
You ______. Don’t talk on the phone.
A.will drive
B.are driving
C.were driving
D.have driven