PR间期固定,但部分P波后无QRS波群()
A.第一度房室传导阻滞
B.第二度Ⅰ型房室传导阻滞
C.第二度Ⅱ型房室传导阻滞
D.第三度房室传导阻滞
E.高度房室传导阻滞
参考答案:C
China always plays ____ active part in fighting against _____natural disasters.
A./; the
B.an; the
C.an;/
D./; /
假设购买一张永久债券,其市场价格为40元,永久年金为5元,该债券的到期收益率为()。
A.8%
B.10%
C.15%
D.15%