90. --- Who is that gentleman who talked to you just now?

--- He is my uncle _____ marriage.

A．at

B．to

C．by

D．With

（）是R4核心网中MGW之间的接口，用来在R4核心网内承载用户的话音媒体流。

A.Mc接口

B.Nc接口

C.Nb接口

D.Abis接口