Question

8.e.5.3: hierarchy in space
bryant
aced out: crash course kids #25.1
multiple-choice question
scientists use light - years to measure
distance
time
volume

Explanation:

A light - year is defined as the distance that light travels in one year in a vacuum. So scientists use light - years to measure distance, not time (which is measured in units like seconds, minutes, years) or volume (measured in units like cubic meters, liters).

Answer:

A. distance