第21题: [单项选择]二尖瓣狭窄可引起() A. 左心房扩大 B. 左心室扩大 C. 左室壁增厚 D. 主动脉扩张 E. 二尖瓣口血流速度减慢 参考答案:A 答案解析:二尖瓣狭窄,左房内血容量增加,继发左房增大。
第22题: [单项选择]What time is it now A. Seven o’ clock. B. Seven-thirty. C. Eight o’ clock. D. Nine o’ clock. 参考答案:A 答案解析:[听力原文]
W: I think that the game starts at eight.
M: Good. We have an hour to get there.