I think pollution would be one
Started with the assassination of Arch Duke Franz Ferdinand.
The Answer is:
1)They observed the sun's longitude and the moon's phases.
Answer:
the change in birth and death rates
Explanation:
The Supremacy Clause of the Constitution of the United States (Article VI, Clause 2), establishes that the Constitution, federal laws made pursuant to it, and treaties made under its authority, constitute the "supreme Law of the Land", and thus take priority over any conflicting state laws.
