A、Because people in that period believed in the power of God. B、Because people in that period believed in the power of mankind.

W: OK, Professor Johnson. Today, let’s talk about something about American history. It is said that American Revolution period is also called an age of reason. I wonder why?
M: (12) Because in the 18th century, people believed in man’s own nature and the power of human reason. With Franklin as its spokesman, the 18th century America experienced an age of reason and enlightenment.
W: I see. There were a lot of prominent people who founded the USA in the first place. Do you know some of the names?
M: I can recall the first president of our nation, George Washington, who was appointed commander in chief of the Continental army at the outbreak of the War. After victory he was elected president.
W: Look at this picture we took in an exhibition. It seems like a part of the Declaration of Independence!
M: (13-1) It is indeed. It is said that the Declaration of Independence was drafted by four great men in America.
W: (13-2) I guess Thomas Jefferson was one of them.
M: (13-3) You are right! He was also the third president of the USA.
W: Was Benjamin Franklin the second president then? I remember he was called father of America?
M: (14) Nope. Benjamin Franklin was a successful statesman, businessman, scientist and writer. But he was never elected president.
W: Then why was he called father of our country?
M: I bet that has a lot to do with his achievements in the above fields. In fact, he was also the embodiment of American Dream.
W: (15-1) I know that because he was raised in a very poor family and he had little formal education but he worked hard and grabbed each opportunity to fly that high.
M: (15-2) That is the essence of American Dream, isn’t it?
Questions 12 to 15 are based on the conversation you have just heard.
12. Why was the American Revolution period called an age of reason?  
13. What do we learn about Thomas Jefferson?
14. What do we learn about Benjamin Franklin?
15. What is the essence of American Dream?