Most residents of ancient rome lived in

apartment-style buildings.
large, stone coliseums.
small cabins made of wood.
curved, stone structures.

The elite classes of Roman lived in expensive residences. Many poor and lower middle-class Romans lived in crowded, dirty apartments, known as insulae, which was a kind of apartment style building that housed most of the urban citizen population of ancient Rome. These multi-level apartment blocks were built as high and tightly together as possible.

Therefore, the correct answer is the first one, apartment-style buildings.

the deaths of over a million communist soldiers

post-traumatic stress disorder in veterans