Well saying dunno is an error in formal/academic writing. In academic writing you would have to write, i do not know, though.
Ill try but i think your reffering to Goosebumps.
When she was in the grocery store and the owner yelled who let this thirty dog in here
Thomas Hobbes came up with the idea of the social contract in 1657. His ideas were influenced by the English Civil War. He argued the importance of government, saying that society would be in ruins without it. Because of his pessimistic view of people, believing we are all born naturally evil and corrupt, he believed that absolute rule was the only answer. He wanted to form a social contract with the government primarily because he wanted to ensure self-interest. John Locke built off of Hobbes ideas but changed them to fit his own ideals. He wanted the power of government to come from the people's consent, keeping the rulers accountable to their people, yet in power.
Hope that helps!
The purpose is for the author to make the reader want to read and find out more since most likely the first book ended in a cliff hanger; they want the reader to read more and find out more of what will happen.