Which is a method that scientists use to determine the composition of earth's layers?

1, Comparing the composition of the crust to other bodies in the solar system

2. By studying things from Earths layers that have been pushed up through the cracks of the crust.

3.By measuring diffrent kinds of vibration from earthquakes

3.By doing laboratory expirements

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answer; the correct answer to the above statement is to increase the production of milk in a herd of milk cows, the highest producing cows were chosen as the mother;