These structures are called Vestigial structures, they resemble structures from the organism's ancestors, but don't have a real purpose for them now.
Pray this helps you :)
I believe that the youth movement originated with the baby boomers, the huge generation born after the world war II. By 1970, 58.2 % of the population in America was under the age of 35 years. The economic boom of the 1950s meant more families could afford to send their children to College. College life gave the young people a sense of freedom and independence. It was on college campuses across the nation that youth protest movements began and reached their peak.
As trees takes in carbon dioxide and gives out oxygen, it is almost similar to how our lungs work in our respiratory system. As you know, lungs remove carbon dioxide from our body and transports oxygen in order for us to survive. So the tropical rainforests gives out oxygen for our survival needs, which is somewhat similar.
I hope you understand lawl
I dont know if have this but... i have this questio and it is c