Answer:
3) bb
4) the evidence is that not every generation has it, it skips generations, and it gets passed down even though the parents didn't have it. there are carriers
Explanation:
Group 2
Excretory system implys the removal of waste.
D. Integumentary
The human body is covered with skin and it is the largest organ in the human body. It's protects us from the outside harm.
Metallic bonds are the force of attraction between positive metal ions and the valence electrons that are constantly moving around them. The ions form a lattice-like structure held together by the metallic bonds. Metallic bonds explain why metals can conduct electricity and bend without breaking