Which two statements are true about a system?
a system is a group of objects analyzed as one unit.
energy that moves across system boundaries is conserved.
there’s only one way to define the boundaries of a system.
all systems are made by humans

The correct options are:

1. A system is a group of objects analyzed as one unit.

2. Energy that moves across system boundaries is conserved.

Explanation:

A system is defined as group of interrelated or interacting items existing as a single unit or a whole to achieve a specific objective.Energy lost by the system is equal to the energy gained by the surroundings.

Two statements are true about a system:

The answer is the first and second one. I hope this helps.

Explanation:

1 - wave length

2 - amplitude

3 - crest

4 - trough

explanation:

duh.

gas and liquid