Which system produces chemical messengers known as hormones: which system produces chemical messengers known as hormones: integumentary system muscular system immune system endocrine system nervous system?

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.

equal distribution i think.

helicase, i think thats it

sound moves fastest in solids because the molecules are tightly packed and it allows sound to vibrate