What geographic feature served as the biggest catalyst for the westward expansion
2 answers:
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Answer: A medium-mass star will become a white dwarf at the end of it's life cycle.
Explanation:
The life cycle of a medium-mass star (according to the picture, which I can attach for you if you want) is:
1. Interstellar Cloud
2. Protostar
3. Small Star
4. Red Giant
5. Planetary Nebula
6. White Dwarf
