get sb down后面加doing还是to do?

给你几个句子吧,有些东西 不能直接说的要细细品味：get sb down
（非正式）Doing the same thing everyday can get you down.
get down to sth
After lunch we get down to discussing the issue of pay.
你那短语 就象是转化为被动一样.你知道了吧