D) The AV valves are supported by chordae tendineae so that they do not blow back up into the atria during ventricular contraction.
The more intense the force is of the car hitting something and the faster it goes the longer it's going to take to stop going forward. Lighter cars accelerate faster than heavy cars.
In the science world today, both the natural regeneration and stem cell therapy can be used to generate new cells and both processes have thier advantages and disadvantages. The following are the advantages of natural regeneration over stem cell transplants:
1. Natural regeneration is cheaper compares to stem cell transplant.
2. The process of natural regeneration is safe and does not involve the fear of unknown, long time effects like that of stem cell transplant.
3. Naturally regenerated cells can not be rejected by the patient's body but a stem cell transplanted cell can be rejected by the patient's body.
Answer: Ice cores.
Explanation: Ice cores are commonly studied by scientists to find out what the climate was like decades and centuries ago.