对电子表格的编辑，主要是对表格中的数据进行（）和替换等操作。

A.增加

B.删除

C.修改

D.查找

— How long is it _____ you picked up your badminton training?

— It was not until my finance became better in last December _____ I started the training.

A．since; that

B．before; when

C．until; that

D．that; when