The answer is A. It twirls like a helix and has 2 strands
Help ease people through the withdrawal process.
The largest vein in an animal's body is in fact the Vena Cava.
Hope I helped :)
The answer is probably B because white blood cells are part of the immune system, so help to fight diseases. The circulatory system helps to move the white blood cell around the body. Also, pathogens are disease causing organisms, and as you can see, they all relate very well. Hope i helped, have a nice day.
