Thelifeexpectancyisthelengthoftimethatapersonisnormally...
问题详情：Thelifeexpectancyisthelengthoftimethatapersonisnormallylikelytolive.Asitincreasesnowadays,theAveragepersonlivesbeyondtheageofretirement.Asaresult,theelderlymakeupanever-increasingpercentageofs...