China and India are definitely in the top three, as they both have over a billion of people (China still more but India is about to catch up). Number 3 is actually the US! so it's China India and the United States
The second largest city in Brazil is Rio de Janeiro, while the third biggest is the capital Brasilia. Rio de Janeiro has an estimated population of around 6,5 million people while Brasilia has little less than 3 million. This makes Rio de Janeiro more than twice bigger in population than the capital of Brazil, Brasilia. But there's something interesting in here in the background, in the past 6 years the population of the second Rio de Janeiro has only increased by little over 9%, while Brasilia's population has increased by around 20% which is more than twice in increase, so if that trend continues in the coming few decades Brasilia will come on top of Rio de Janeiro very quickly.
Answer: a circle and uniform motion
Explanation:
Ptolemy's model of the universe placed the Earth motionless in the center of a universe subject to uniform circular motion, the other planets, the Moon and the Sun describe complicated orbits around it.
As Ptolemy was a respected astronomer and geographer, this idea was accepted for a long time, until Copernicus arrived with the new model (heliocentric theory) that placed the Sun at the center wir the Earth and other planets describing circular orbits around the star. However, <u>the heliocentric theory did not explain why planets orbit the Sun at different speeds at different times, because this model used only circular orbits in uniform motion. </u>
All of this is due to the Greek ideologies of perfect form and motion with a perfect circle. But then, the astronomer Johannes Kepler refined the Copernicus' heliocentric theory with the introduction of <u>elliptical orbits.</u>
The Roman–Persian Wars were a series of conflicts between states of the Greco-Roman world and two successive Iranian empires: the Parthian and the Sasanian. Battles between the Parthian Empire and the Roman Republic began in 66 BC; wars began under the late Republic, and continued through the Roman (later Byzantine) and Sasanian empires. Various vassal kingdoms and allied nomadic nations in the form of buffer states and proxies also played a role. The wars were ended by the Arab Muslim Conquests, which led to the fall of the Sasanian Empire and huge territorial losses for the Byzantine Empire, shortly after the end of the last war between them.
Although warfare between the Romans and Persians continued over seven centuries, the frontier, aside from shifts in the north, remained largely stable. A game of tug of war ensued: towns, fortifications, and provinces were continually sacked, captured, destroyed, and traded. Neither side had the logistical strength or manpower to maintain such lengthy campaigns far from their borders, and thus neither could advance too far without risking stretching its frontiers too thin. Both sides did make conquests beyond the border, but in time the balance was almost always restored. Although initially different in military tactics, the armies of both sides gradually adopted from each other and by the second half of the 6th century they were similar and evenly matched.[1]
The expense of resources during the Roman–Persian Wars ultimately proved catastrophic for both empires. The prolonged and escalating warfare of the 6th and 7th centuries left them exhausted and vulnerable in the face of the sudden emergence and expansion of the Caliphate, whose forces invaded both empires only a few years after the end of the last Roman–Persian war. Benefiting from their weakened condition, the Arab Muslim armies swiftly conquered the entire Sasanian Empire, and deprived the Eastern Roman Empire of its territories in the Levant, the Caucasus, Egypt, and the rest of North Africa. Over the following centuries, more of the Eastern Roman Empire came under Muslim rule.
https://en.wikipedia.org/wiki/Roman%E2%80%93Persian_Wars
Lava flow is actually quite slow, and in most cases you can outrun lava.
What kills people in the case of volcanic activity is either
-<span>Pyroclastic Flows (hot air and ash traveling fast)
or
-landslides or mudslides - those often kill entire villages since they can happen far from the volcano too.
</span>
