单纯二尖瓣狭窄早期最常见的X线改变是
A.右侧胸腔积液B.右房区域的双房影C.心内钙化影D.肺动脉段突出E.Kerlry线
参考答案:D
如图,AB是⊙O的直径,M是⊙O上的一点,MN⊥AB,垂足为N,P,Q分别为弧AM、弧BM上一点(不与端点重合)如果∠MNP=∠MNQ,给出下列结论:
①∠1=∠2;②∠P+∠Q=180°;③∠Q=∠PMN;④MN2=PN•QN;⑤PM=QM
其中结论正确的序号是( )
A.①②③
B.①③④
C.①③⑤
D.④⑤
Which of the following will increase the positive stability of your vessel?().
A.Loading weight on deck
B.Discharging weight from lower decks
C.Shifting weight from upper to lower decks
D.Shifting weight from lower to upper decks