What was added to the tops of towers in order to provide stone shields for more effective defense?

Native Americans share a common identity linked to all of the following EXCEPT

a) tribal languages. b) pre-contact ancestry. c) conquest history. d) forms of cultural expression.

What is dissonance?

a) the harsh sound created when two or more notes clash b) contrasting notes that create a harmony that sounds "sweet" and pleasing c) the silence omitted by an elided cadence d) a rhythm that flows consistently