get down to something        
phrasal verb with get verb uk/ɡet/ us/ɡet/  getting | got | got or gotten
B2 开始认真对待;开始认真注意;开始努力做
to start to direct your efforts and attention towards something
  I've got a lot of work to do, but I can't seem to get down to it. 我有好多工作要做,可我好像就是没法安下心来去做。 
 [ + -ing verb ] UK I must get down to booking the hotels. 我得开始预订我们的旅馆了。