计算维持保证金不需要用到的数据是（）。
A、行权价
B、标的收盘价
C、合约前结算价
D、隐含波动率
参考答案：D
分光光度计指针不够，通常检查原因时。首先考虑预热时间是否短了。
A continuous sounding of a fog-signal apparatus indicates（）.
A.the vessel is in distress
B.the vessel has completed loading dangerous cargo
C.it is safe to pass
D.the vessel is anchored
