白喉是（）。
A.假膜性炎
B.炎性积液
C.大量红细胞漏出
D.有脓腔形成
E.渗出物中有大量红细胞
参考答案：A
—Do you know if Mary has got married John?
—Yes, They have for nearly a year.
A．to ; married
B．to ; been married
C．with ; got married
D．/ ; been married
某投资组合的平均收益率为14%，收益率标准差为21%，贝塔值为1.15。若无风险利率为6%，则该投资组合的夏普指数为（）。
A.0.07
B.0.13
C.0.21
D.0.38
