forms quarts / flies forming occurs over a frequency of 300000000 age which is considered a very long space to a mankind
if fly occurs then fly occurs. archery is in_use_fifty_thousand_years_ago. if sailplane does not occur then fly occurs. moon's_orbital_period_around_earth is not 28_days. if fly does not occur then fly occurs. if sailplane occurs then fly occurs. moon's_orbital_period_around_earth is 28_days. century is time_period. flies is not space. century is 100_years.