Our muscles are attached to our skeleton to help us move. If we had no skeleton then our muscles would hang limply, making it harder for us to move.
Here you need to put if you have any questions about the material you are learning. If you have none i would consider putting that you have none.
1st of all arteries have a thick walls while veins have have a thin wall
Answer to why arteries have thick walls: arteries have thick walls because blood flows inside them with high pressure and with a high speed
I think the roots are the most important part of a plant because without the roots the stem and leaves would have no job
