Why does Pausch talk about football?
He wants to tell the audience that he did not
achieve all of his goals.
He wants to let the audience know that mastering
the basics is key to achieving goals.
He wants to explain how to be a good football
coach to people who are interested in football.
He wants the audience to try playing football so
they can enjoy a similar experience.

He wants to let the audience know that mastering  the basics is key to achieving goals.

Explanation:

The question above is related to the speech entitled "Achieving your Childhood Dreams," by Randy Pausch.  

Along his speech, he mentioned about his childhood dreams of playing in the National Football League and becoming an author of an article in the World Book Encyclopedia. However, he didn't pursue such goals in life and by mentioning it, he wanted the audience to know that "mastering the basics is key to achieving goals."

Although he had a coach who'd helped him master football, he still didn't become part of the NFL. However, for him, he was able to have a valuable experience which he treasured.

Such experience allowed him to master the basic skills which are very important in achieving one's goal.

So, this explains the answer.

the students want to see the great sphinx of giza, which is very popular with tourists.

the rocket launch by showing how the population around it changes its behavior as the earth's influence over the martian planet when he uses the term "green star".

explanation: