To narrow one's focus in order to become an expert at producing a particular good or service is to . A.
specialize
B.
expand
C.
enlarge
D.
contract

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.

he armenian genocide, also known as the armenian holocaust, was the ottoman government's systematic extermination of 1.5 million armenians, mostly citizens within the ottoman empire.

explanation: