Answer:
circulatory and respiratory
Explanation:
The circulatory and respiratory systems work together to give the body the oxygen it needs.
180 million years is the correct answer
B.Some of the ball’s energy is transformed to thermal energy.
Explanation: Law of conservation of energy states that energy can neither be formed nor be destroyed but it can only be transformed from one form to another form
D. do all of these...........
Chromatin is dna that makes a chromosome and chromosomes are different dna strands in a cell, sister chromatids are identical pieces of dna