Why does soda pop make you burp?

Who invented soda pop? Why was Coca-Cola, Pepsi & Dr. Pepper originally sold as medicine? How do they get the bubbles in soda pop? For free home activities sign-up at www.WhoSmarted.com See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.