女,38岁,心脏超声心动图提示:二尖瓣脱垂,体检时可能存在的体征是()
A.收缩早期喀喇音
B.开瓣音
C.收缩期前奔马律
D.收缩中、晚期喀喇音
E.舒张中、晚期喀喇音
参考答案:D
国债是一个特殊的债务范畴。它与私债的本质区别在于发行的( )或担保物不同。
A.形成
B.信用基础
C.依据
D.信用担保
It was now clear that no such weapons were manufactured and none been found.
A.was found
B.were founded
C.has been found
D.have been founded