A: maintenance is the final stage --> thus this answer is the only appropriate one.
Wow, good job. You're so big brained. /g
Answer:
The umbilical vein is connected with the vena cava through ductus venosus (structure B).
The Pulmonary artery is connected with the aorta through the ductus arteriosus (structure D)
Explanation:
The diagram depicts the mother and fetal circulation. Oxygenated blood enters the fetus through the umbilical vein. While some of this flow is diverted towards the developing liver vessels, the majority flows directly into the inferior vena cava, bypassing the liver by means of a transient fetal vessel called the ductus venosus.
In the normal postnatal circulation all of the blood coming from the pulmonary artery flows towards the lungs. In the fetus, however, a significant fraction of this blood is shunted into the Aorta instead through another transient fetal vessel known as the ductus arteriosus.
<span>Answer: Air, a piece of paper, and a lit cigarette
Fire is the product of oxidation, a chemical reaction that uses oxygen. To create fire, you will need 3 things: oxygen, heat source and fuel to burn. Oxygen comes from the air. The piece of paper will be the burned fuel. Lit cigarette provide the heat source.</span>
Answer:when most calm
Explanation:bc u won’t have a faster heart rate
