You have to go your 12 years of elementary-high-school then another 4 years in college to get your bachelors degree in teaching<span />
You could write a paragraph on the invention of toilet paper or the invention of electricity or the invention of the phone. Before the invention of toilet paper, people had to use... well anything from newspapers to magazines. Before electricity, people had to work during daylight hours (it was more confining of time). before the invention of the phone, messages had to be delivered in person or by letters.
here are some ideas to get you started. good luck!!