A condition where pathogens are present and multiplying in the blood is called a condition - septicemia
Septicemia or sepsis is a blood infection or blood poisoning. This requires immediate medical diagnosis. Its symptoms include - fever, chills, difficulty in breathing, nausea and vomiting, low blood pressure, faster heart rate etc.
Volcanic activity files the air w carbon dioxide
Cartilaginous fish do not contain any bones - their skeleton is made up of cartilage.
Answer:
An higher being, or God created them.
Explanation:
This may not be the exact answer you are looking for, but lots of people looked to higher beings to make sense of the world before science.
This is true that the pressure in the mesosphere is so low that a person could not be in this layer without a spacesuit.
The mesosphere is the region of the earth's atmosphere which is above the stratosphere and below the thermosphere. It has a very low temperature and pressure. The top of the mesosphere is the coldest part of Earth's atmosphere.