significant evidence significant evolution significant example significant examples significant excess significant expansion significant expenditure significant expense significant expenses significant experience significant experiences significant expertise significant exposure significant extent significant external significant extra significant fact significant factor significant factors significant facts significant fall significant family significant feature significant features significant figure significant figures significant financial significant financial investment significant financial resources significant financing significant find significant finding significant findings significant fines significant fire significant first significant fiscal significant flaws significant flexibility significant flooding significant fluctuations significant focus significant food significant for several reasons significant force significant form significant fraction significant functional significant funding significant funds significant further significant gain significant gains significant gap significant gaps significant gender significant gender differences significant global significant government significant ground significant group significant growth significant hair significant harm significant hazard significant hazards significant head significant health significant health benefits significant health problems significant health risk significant hearing significant help significant higher significant historic significant historical significant history significant homology significant human significant humanitarian significant hurdles significant impact significant impact on the environment significant impacts significant impairment significant impediment significant implications significant importance significant improvement significant improvements significant in terms significant incident significant incidents significant income significant increase significant increase in the number significant increases significant indicator significant indirect