LEFTISTS AGAIN GAIN IN FRENCH ELECTIONS, TAKING 21 BIG CITIES
French opposition left makes considerable gains in nationwide munic voting on Mar 20, but is defeated in Paris as ex-Prime Min Jacques Chirac wins mayoral election; Socialist-Communist coalition wins control of 21 major cities adding to 33 cities it took in 1st-round of elections; controls more than 3/4 of country's largest cities; leftist leaders Mitterrand and Marchais laud outcome; illus (L)
