The US Constitution is adaptable because the Founding Fathers deliberately made it relatively vague--meaning that they didn't get too specific because they knew it would have to endure in the future, when minds and society would be greatly different. It's also adaptable because it allows for amendments, which keep the document relevant with modern times.
The development of trade during the middle age increased thanks to the change given in the agriculture, which gave money, industry and markets a bigger importance in economy. The agriculture production was more than the consumption, which meant the creation of wider markets out of the areas. Besides, with the end of multiple wars, the population increased and new trade routes were created.
Killing a lot of people and causing the 9/11 attacks
The similarities between Greek and Roman government were that both favored aristocratic rule, both believed that their citizens should have a right to participate in politics and military service and they both governments were made up of several city states.
The differences were that the Greek government did not have political parties. If a Roman official was unwanted in office, the citizens would vote him off and just be glad that he wasn't governing them anymore, but if a Greek official was unwanted he'd be kicked off, ostracized, and banned from Athens for 10 years. Also, the Romans didn't allow women to vote, but women of upper class citizenship could influence their husband's vote.
Sorry, if the information isn't enough.
