题型:选择题 At the seventh International Ballet Competitions , Fernando Bujones won the first gold medal ever to an American male dancer .A.awardedB.to be awardedC.being awardedD.should be awarded 查看答案
题型:单项选择题 正常三尖瓣与二尖瓣血流多普勒频谱有什么不同()。A.三尖瓣血流频谱呈负向,二尖瓣则呈正向B.三尖瓣血流频谱缺乏收缩期部分C.三尖瓣血流频谱幅度(速度)明显大于二尖瓣血流D.三尖瓣血流频谱幅度(速度)小于二尖瓣E.三尖瓣血流舒张早期速度大于二尖瓣 查看答案