[简答]  【完形填空题】Choosethebestanswerforeachblank tocompletethefollowingpassages.TheNewDreamIsn’tAmerican  Everyyear,millionsofpeople theglobemaketheessentiallyeconomicchoiceof tocometotheUnitedStates---legallyor.Butinthepast18monthsthecalculusbehindthatdecisionhas.ManyimmigrantsareleavingtheUnitedStates---willinglyandunwillingly---andountlessothersaredecidingnottocome.Thereasons:tougherenforcementand,alowingU.S.economyandimpressivegrowthindevelopingcountries,wheremanyimmigrantshailfrom.