Which best explains why a washing machine represents an open system. water and power come from external sources. < ans b. most washers can use a variety of laundry detergent brands. c. the amount of wash in a load varies. d. it has multiple cycles, such as wash and spin

A. water and power come from external sources.

Explanation:

To determine if a system is a closed or an open one, we need to determine if it interacts with the external environment.

A closed system is the one that doesn't have interaction with the external environment, mass or energy is never transfered from the outside of the system.

An open system regularly exchanges feedback with an external environment.  

In this case as the power and water, which are importat for the functioning of the washing machine, come from an external source, we are refering to an open system.

disease was the number one killer of native peoples. they had had little exposure to the diseases of europe. this led to some villages being almost completely wiped out and some tribes destroyed.

not really sure i needed the points. sorry