Thewealthofacountryshouldbemeasured________thehealthandhappinessofitspeopleaswellasthematerialgoodsitcanproduce.
Tostudyaforeignlanguage,__________.
WhenIcamethroughthecustomsattheairport,Ihadtopay________onaclockIhadbought.
When workers are organized in trade unions, employers find it hard to lay them ________.
________,Johnhasbeentoseveralforeigncountries.