Which statement is the best description of the Milky Way galaxy?
A: a group of stars, dust, and planets held together by gravity

The flower petals of a hydrangea plant change color as the acidity of the soil changes. The color changes are directly related to which factor?
A: environmental conditions

Which gas makes up the greatest percentage of Earth's atmosphere?
A: nitrogen

What advantage do sea stars gain from having radial symmetry?
A:
They sense predators and potential food from all directions.