The earliest member of the horse family was the size of a

1.rodent
2.terrier
3.lion
4.none of the above

2.Terrier

Explanation:

The oldest fossil found of a horse is about 55 million years old called Eohippus. Unlike horses as we see them today, it was from the size of a small dog. These were found at North America and Europe. They had a shorter head, with a small jaw and a shorter stature (20 to 40 cm). Then slowly evolved to what domestic horses are today.

explanation:

on disadvantage of hydroelectric power is the cost. another disadvantage of using hydroelectric power is finding a water source powerful enough to harvest hydroelectric power.

i think it is dna, i'm not totally sure but i think it might be.