The research demonstrated that <span>individuals improve most mental abilities during adulthood and then experience a gradual decline.
After people surpassing the mid-age, regeneration of the brain cells will also start to decline, which resulted in the impairment of cognitive ability that played a crucial role in our analytic ability.</span>
What grade is this? 6TH 7TH OR 8TH?
Nomadic people like mongols, huns, and khitans
