Thelifeexpectancyisthelengthoftimethatapersonisnormally...
問題詳情：Thelifeexpectancyisthelengthoftimethatapersonisnormallylikelytolive.Asitincreasesnowadays,theAveragepersonlivesbeyondtheageofretirement.Asaresult,theelderlymakeupanever-increasingpercentageofs...