营业成本是指企业经营业务所发生的实际成本总额，包括主营业务成本和（）业务成本。
A.兼营
B.其他
C.第二
D.次要
参考答案：B
病毒性心肌炎最常见的病原体是（）
A.流感病毒
B.埃可病毒
C.轮状病毒
D.柯萨奇病毒
E.腺病毒
--I once got lost during my first visit to Beijing.
-- Oh, did you? You ____ me as your guide.
A．might have asked
B．could ask
C．would have asked
D．would ask
