Two of Robeline High School's first-string basketball players have admitted to Ruston police they staged five gasoline station hold-ups throughout Louisiana and Arkansas during the past two months.Latest of these was the robbery of Brooks Gulf Station here last Saturday night when $1 20 was reported taken at gun-point by two crew-cut teen-agers.It was through intensive detective work from clues obtained in the investigation of the robbery here that Ruston police were able to apprehend the two youths.They are listed as Buel Dowden, 18, and Thomas E. Jordan, 17, both seniors of Robeline High School, first string ] basketball players and lifelong friends.