Answer:
The Inca road system formed a network known as the royal highway or qhapaq ñan, which became an invaluable part of the Inca empire, not only facilitating the movement of armies, people, and goods but also providing an important physical symbol of imperial control. Across plains, deserts, and mountains, the network connected settlements and administrative centres. Well-built and lasting, many roads included bridges, causeways, stairways, and also had small stations (chaskiwasi) and sometimes larger, more luxurious complexes (tambos) dotted along every 20 km or so, where travellers could spend the night and refresh.
Explanation:
The situation that caused stress on public services offered in American cities during the late 19th century and early 20th century was: Migration from farms to cities.
Migration from farms to cities massively increased the number of population that should be eligible to obtain government benefits in that area destination. This lead to an increase of work load for government workers in that period and caused stress on public services offered by the cities.
I would say language diffusion
