Isitnecessarytolearnwhenweare50s，60soreven70s?Mostpe...
问题详情： Isitnecessarytolearnwhenweare50s，60soreven70s?Mostpeopleconsiderwhenthey getretired，theyaresupposedtobecompletelylaidback，dosomethingfun，orhangaround．36 It’sparticularlyimportanttotheelder...