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