Question

the fluid that runs through the circulatory system
95 percent water
the lower part of the heart
a gas expelled by the body through the lungs
the upper part of the heart

Explanation:

1. The fluid that runs through the circulatory system is blood. It transports oxygen, nutrients, and waste products.
2. A substance that is 95 percent water is saliva. Saliva has various functions like moistening food.
3. The lower part of the heart consists of the ventricles which pump blood out of the heart.
4. A gas expelled by the body through the lungs is carbon - dioxide, a waste product of cellular respiration.
5. The upper part of the heart is the atria which receive blood into the heart.

Answer:

1. blood
2. saliva
3. ventricles
4. carbon - dioxide
5. atria