-catchupfrombehind;Latecomersbecomethefirst.;latecomersgettingaheadofothers;Newcomersarepromotedovertheheadsofhisseniors.;Newcomersgaintheupperhandontheold.;Successorsexcelthepredecessors.;Thebackwardcaughtupwiththeadvanced.;Thelatecomerssurpasstheearlystarters.;Thenewcomerhasoutdonetheoldhands.;Theyoungergenerationoutstripstheold.;thosefrombehindcatchingupandsurpassingthoseinfront;Thosewhocomelatesomehowgettotheforefront.