Oceanic crust has been forming on Earth for over 4 billion years, all of the sea floor older than <span>about 200 million years. </span>
so if you look up things that can cause an asthma attack it will also show that viruses and bacteria are a cause. with asthma you lungs could already be inflamed as well as your air way wich makes it harder to breath. when you have c-19 it will inflame your lungs even more so it makes it even harder to breath given an asthma attack. more asthma attack now are probably caused by c-19 because it is all over the place and the percent of asthma attack by virus has dramatically increased.
Answer:
provide protection against pathogens
Explanation:
It's controversial because the best source of stem cells is a human embryo (an aborted fetus).
