For this reason, it is important to develop and maintain cardiovascular fitness early in life. The heart is a muscle and it gets stronger with the right types of exercise. The heart acts as a pump to supply blood to your working muscles
D. nephrons - the structural and funtional unit of kidney
That’s a good question, sometimes I believe it’s because other medications could be interfering with its mechanisms; also not to account for failure necessarily, it is to prevent a law suite. If the claim was 100% effective and for some unknown reason someone became pregnant, the company who manufactures and markets that contraceptive could be held liable.
I hope this helps :)
Answer:
They protect you against illness and disease, they are also part of the immune system.
Explanation:
They flow through your bloodstream to fight viruses, bacteria, and other foreign invaders that threaten your health.
When you get sick, your body makes more white blood cells to fight the bacteria, viruses, or other foreign substances causing your illness. This increases your white blood count
Hope this helps
Mark brainliest if it helps
