--What are you doing this weekend?

--I haven't decided yet．____________?

--Well, I thought we could have another family party．

A．What

B．All right

C．Why

D．Pardon

当替代品的质量等级高于标准交割等级时，交割价格要进行( )。

A．升水
B．贴水
C．平均
D．随市场行情适时进行调整