every other - alternate
　　fall behind - lag; fail to accomplish something on time
　　fall through - fail to happen or be completed
　　far cry form - completely different from;a long way
　　feel like - have a desire or wish for
　　feel up to - feel well enough to or be capabele of
　　few and far between - not happening often; rate
　　figure out - determine; reason out by thinking
　　fill in for -take another’s place
　　fill sb.in - tell what sb. should know
　　fish out of water - out of one’s element or natural environment
　　flying colors -success,victory
　　for good - permanently; forever
　　for the time being - for now; temporarily