心室舒张时,防止血液逆流的装置有()
A.二尖瓣和三尖瓣
B.肺动脉瓣和三尖瓣
C.主动脉瓣和二尖瓣
D.主动脉瓣和三尖瓣
E.主动脉瓣和肺动脉瓣
参考答案:E
In our class _____ of the students _____ girls. [ ]
A. three fifths; are
B. three fifth; are
C. three fifths; is
D. three fifth; is
______是企业财务体系中最基本、最高层次的法规。
A.《企业会计准则》 B.《企业财务通则》C.《企业会计制度》 D.《财务管理规定》