It was not until early this morning _______ my father came back from work, which surprised us.

A．when

B．where

C．that

D．who

1971年，中国取得的第一个外交成就是[ ]

A．与美国关系正常化          

B．恢复在联合国的合法地位

C．中日建交                  

D．中苏建交