1. this is not physics this is anatomy.
2.circulatory system is the flow of blood through the vena cava, right artrium, right ventricle, pulmonary valve, pulmonary ventricle, left atrium, left ventricle, arteries, capillaries, veins vena cava. digestive system is food through the esophagus, stomach, etc. no direct relation.
A.
since they do not have a definite volume, this causes it to spread out in the air
Yes water is liquid.
Explanation: At room temperature (anywhere from zero degree centigrade to 100 degrees centigrade), water is found in a liquid state. This is because of the tiny, weak hydrogen bonds which, in their billions, hold water molecules together for small fractions of a second.