Answer:
1.Atria push blood into the ventricles
2.Venticles push blood out of the heart.
A biggie: the transcontinental railroad. Because it would economically improve wherever it was, both the North and the South competed for the railroad to be in their respective territory, evidenced by the Kansas-Nebraska Act and the Gadsen Purchase and induction of California as a free state in 1860.
In addition: people could get land cheap because it was abundant and might leave to start afresh economically.
There's other stuff I can't remember as clearly, but there's a little and I hope it helps :)
The lowland areas of Latin America are very important because of multiple reasons. The majority of the agriculture and farming of animals is taking place in the areas like this, so the food sector is directly connected with them. On top of the agricultural production, these lowlands produce a lot of food on their own. The industries that use as their main material also are directly dependent on these lowlands, as they are mostly covered with numerous types of high quality tropical tree species. There's thousands of species of plants that are used in the medicine, so the pharmacies are also very dependent on them. All in all, these lowlands managed to contribute a lot in the economy, health, and general well being of the Latin American countries.
Https://maps.google.com/maps?oe=UTF-8&hl=en-us&client=safari&um=1&ie=UTF-8&fb=1&gl=us&entry=s&sa=X&ll=21.4691137,-78.6568942&z=5&ftid=0x8eb9e309d5a038b7:0xc67ecf32cac5dbdc&q=Caribbean&gmm=CgIgAQ%3D%3D&ved=2ahUKEwiZndPamdzdAhUPSN8KHQXoD4AQ8gEwAHoECAoQAQ
This is true.
The definition of megalopolis is that it is a large urban area, huge and densely populated. St. Petersburg is definitely one, however, Miami is relatively small compared to other megalopolises so it might not fall within that category.
