下列心脏病者施行非心脏手术,其耐受力最差的是()
A.非发绀型先天性心脏病
B.高血压心脏病
C.风湿性心脏病
D.急性心肌炎
E.冠状动脉硬化性心脏病
参考答案:D
Questions 1-4
According to the man, how many study circles are there annually in Sweden today?()
A.200,000.
B.350,000.
C.2,500,000.
D.15,000,000.
直流电动机的调速方法有哪向种?各有何利弊?