Answer:
B.Lubricating cartilage at joints
Pretty sure it would be the nerves attatched to the heart valve
Matter and electricity. i hope this answer has come to your pleasing
Adaptions are basically add-ons and/or updates while variations are like different types.
Heya!!
I just took the test and the true answer would be C: Birds have feathers.
You have to think of the Unique Anatomy of a bird.
