《统计法》规定，统计调查应当以周期性普查为主体，以抽样调查为基础，以必要的统计报表、重点调查等为补充，搜集、整理基本统计资料。( )

--- There is ________dark stain(污渍) on my coat. Who left it?

---- It’s me, Dad. I did it just for ______ fun.

A．a ; the

B．a; /

C．the; the

D．the; /