When forces acting on an object are , the object's motion is constant. A.
balanced
B.
strong
C.
invisible
D.
changing

A.) Balanced

Explanation:

If two individual forces are of equal magnitude and opposite direction, then the forces are said to be balanced. An object is said to be acted upon by an unbalanced force only when there is an individual force that is not being balanced by a force of equal magnitude and in the opposite direction.

the answer is d.) homologous; have mammary glands

layer 3 is younger than layer 6.