(2016·安徽江淮名校二次联考)With time flying，people become aged.Then many people even in their middle age often start to notice that their memory and mental clarity are not what they used to be.We suddenly can't remember __1__ we put the keys just a moment ago，or an old friend's name，or the name of an old band we used to love.As the brain __2__，we refer to these occurrences as “senior moments”．__3__ seemingly innocent，this loss of mental focus can potentially have a (n) __4__ effect on our social and __5__ well－being.
