两种药物合用，能产生毒性反应或者副作用的配伍关系是（）
A.相须
B.相使
C.相反
D.相杀
E.相畏
参考答案：C
投资组合保险策略的支付曲线是凹线。（）
—_______?
—No, it isn't. It's her dictionary. [ ]
A. Is this a dictionary
B. Is this your dictionary
C. It's dictionary
D. Is this her dictionary
