a foot in both camps脚踏两条船
a foot in the door开始渗入
fall on one's feet幸运
find one's feet适应；熟悉
get a foot in得到机会加入
have cold feet胆怯；畏缩不前
keep one's feet站稳；不跌倒
my foot我不信
put a foot wrong做错；说错
put one's best foot forward尽量快走；尽最大努力
put one's feet up脚平放着休息
put one's foot down拿定主意，坚持立场；开快车
put one's foot in it弄糟了；惹起麻烦
set foot in进入；踏上