Question

________ I got back, I found my mother cooking for me.

A．When

B．Before

C．Since

D．Although

Answer 1

A

When当……时；Before在……之前；Since由于，自从……以来；Although虽然，尽管。句意：当我回来时，我发现我的母亲正在为我做饭。结合语境可知选A。