英语翻译Why are old people happier?Some scientists suggest older

英语翻译
Why are old people happier?Some scientists suggest older people may expect life to be harder and learn to live with it,or they’re more realistic abour their goals ,only setting ones that they know they are achieve .But Carstensen thinks that with time running out,older people have learned to focus on things that make them happy and let go of those that don’t.