Cell wall: strong; supporting layer around the cell membrane in plant cells
Answer:
Each time your heart beats, an electrical signal travels through the heart. An EKG can show if your heart is beating at a normal rate and strength. It also helps show the size and position of your heart's chambers. An abnormal EKG can be a sign of heart disease or damage.
I believe the answer is A
Sun heat highly temperature. water was can vapor atmosphere
