51.   Earlier research suggests that the protective effects of the new regimen persist for at least six months.

52.   Even so, problems persist for the economy.

53.   Extending a pattern that has persisted for more than a year, shoppers punished most apparel retailers.

54.   FAU officials say they allowed the conflicts to persist for so long because they were trying to work through them.

55.   Finally investors are reacting to big gaps in performance that have persisted for the past several years.

56.   For years I persisted.

57.   For diagnosis, symptoms must persist for more than one month but they may surface immediately.

58.   Given plenty of sun and good drainage, it will persist for decades even in poor soil.

59.   He added that overtime will persist for several months.

60.   He developed laryngitis the next day, and problems persisted for several months.