药材"红芪"的原植物是（）
A.金翼黄芪
B.多花黄芪
C.塘古尔黄芪
D.橡果黄芪
E.多序岩黄芪
参考答案：E
一旦看涨期权或看跌期权的买卖双方履行了期权合约，双方的交易部位就转换成标的物的交易部位。（）
Mr. Li is absent today. What do you consider ________ to him?
A．happens
B．is happened
C．happening
D．has happened
