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1. As we have learned from a stellar evolution theory, our Sun will evolve into a red giant in about five billion years from now. The size of the Sun will extend up to at least the orbit of Mars. What do you think the humans, if they still exist in the future, will do as the Sun evolves into it?

2. You are going to construct a new classification of galaxies. What will you use as criteria of it? Justify your reasons.

Describe the general characteristics, structure, composition, and motion of the Milky Way Galaxy.