Answer:
about 4.6 billion years old. Scientists measure its age by using radioactive decay of isotopes found in meteorites and rocks. The Potassium and Uranium isotopes were formed at the same time as the solar system. The inference is that the age of the rocks and meteorites, is the age of the solar system.
Answer: I believe it is the last line
Explanation:
I agree with the other person, the other sentences are not complete. so in turn it must be: Wagon trains might include 100 wagons.
maybe
