Tariff reduction is the the reduction of taxes on an item being shipped to another country. The answer is the last one. Birth and death rate directly causes population growth or decline. Migration can help people thrive in an environment which means more population. I hope this helps!
I’m not sure exactly what you’re looking for, but the US spent $15m dollars and gained 54% of Mexico’s pre-1836 territory. There’s a nice article on Wikipedia called ‘Mexican Cession’ that seems helpful. Hope this is helpful :)
Earth was able to retain an atmosphere because of its gravity. It is <span>the same force that keeps us anchored to Earth. Molecules in our atmosphere are constantly moving, spurred on by energizing sunlight. If Earth were much less massive, gravity's grip would be weaker.</span>
