All of the following are characteristics of an ethnic group except A.
common practices.

B.
government structure.

C.
customs.

D.
ancestry.

I believe the answer to be B. Government Structure.

Explanation:

My reasoning for this is many countries are made of the same ethic groups, but the government varies. Much like North and South Korea, they are exactly the same people with the same history and culture. However, both countries aren't communism or democratic.

the correct answer is the following is a list of inventions made in the medieval islamic world, especially during the "islamic golden age" (8th to 13th centuries),[1][2] as well as the late medieval period, especially in the emirate of granada and the ottoman empire.

science and technology in the islamic world adopted and preserved knowledge and technologies from contemporary and earlier civilizations, including persia, india, china, and greece-roman antiquity, while making a number of improvements and innovations.

the awnser is that is tru your

lol bye