be fed up with - be out of patience with
　　be on one’s own - live independently
　　be on the safe side - take no chances
　　be out of something - have no longer in supply
　　be tired of - be bored with ,frustrated with
　　be up to ones’ears - be extremely busy
　　be up to someone -be a person’s responsibility
　　be out for -trying to get
　　be out of the question - be unacceptable ,impossible
　　bite off more than one can chew - take on more than one can handle
　　break down - cease to function
　　break the ice - begin to be friendly wuth people one doesn’t know
　　break the news - inform or give bad news
　　brush up on - imporve noe’s knowledge of something through study
　　bump into - meet unexpectedly
　　by and large - in general
　　by heart - by memory
　　by all means - absolutely ,definitely
　　by no means - in no way