强心苷对下述心衰疗效最好的是()
A.高血压引起的心衰
B.严重贫血引起的心衰
C.甲亢引起的心衰
D.维生素B1缺乏引起的心衰
E.病毒感染引起的心衰
参考答案:A
She had to drop out of school _____ her family couldn’t afford the cost of her education.
A.although
B.unless
C.because
D.so
影响机车动力性能的因素有哪些?