Blood cells are produced in the bone marrow and the bone marrow is part of the skeletal system. So the answer would be skeletal system<em>. </em>
Answer:
1. C.) Their cell walls contain chitin
2. C.) Chloroplast
Answer:
I am not sure but I think it is 2
Answer:Dark matter is invisible and does not emit electromagnetic radiation. Dark matter is part of a theory that hypothesis the existence of a counterpart to the particles we know in physics, in order to balance the universe that otherwise would be largely unbalanced right now. However, the theory right now is not yet proven.
Explanation:done
