采用复合标底确定评标基准价，其计算用到的数据有( )。

A．投标人有效报价

B．有效报价的投标人个数

C．招标人标底

D．标底所占评标基准价的权重

E．最高的投标人报价

Your vessel is crossing a narrow channel.A vessel to port is within the channel and crossing your course.She is showing a black cylinder.What is your responsibility?（）

A.hold your course and speed

B.sound the danger signal

C.begin an exchange of passing signals

D.do not cross the channel if you might impede the other vessel