Final answer:
The Etruscans taught the Romans to build arches, fortifications, and an army. As a significant influence in the Italian peninsula, their contributions were integral to early Roman development, including city planning and military tactics.
Step-by-step explanation:
The Etruscans taught the Romans to build arches, fortifications, and an army. As an advanced civilization that thrived from around 900 BCE to 600 BCE, the Etruscans exerted significant influence on the early development of Rome. They are known for constructing walled cities and houses of mud brick, as well as elaborate tumuli tombs, carved into the region's limestone. Their expertise in architecture was inspired by ancient Greece, but with distinctive differences, such as the use of mud-brick and terracotta. The Etruscans fortified their cities by building on high places, a strategy early Rome adopted with its seven hills.Moreover, the Etruscans developed a written language, influenced by the Greek alphabet, and organized into independent city-states. By 600 BCE, they had expanded their territory, including colonizing Rome and creating it as an Etruscan city. Despite being a formidable power in the Italian peninsula, their dominance declined after the naval defeat at the Battle of Cumae in 474 BCE. However, the impact of the Etruscans on Roman military organization and urban planning was lasting, with elements of Etruscan rule embedded within Roman governance up until 509 BCE.In conclusion, the adept knowledge of the Etruscans in building arches and fortifications and their establishment of an army were critical contributions to Roman infrastructure and military prowess, which helped shape the emerging Roman state's early development.