Bythemiddleofthe21stcentury,thevastmajorityoftheworld’spopulationwillbelivingincities_______inthecountry.
Thenewspaperwillhavetoclosedownifitcannotincreaseits________considerably.
Heboughtahouseforhischildren________
Hefound_______difficulttostudymaths.
WhichofthefollowingcountryisnotamemberofOECD?