Answer:
<h2>C. To date rock layers</h2>
Explanation:
<em>They can help determine the relative age of rock layers</em>.
A :-) Sickle cell disease occurs more often among people from parts of the world where malaria is or was common. It is believed that people who carry the sickle cell trait are less likely to have severe forms of malaria.
Hydrogen atoms are compressed
together by the enormous gravitational force
of the sun, causing them to fuse int a helium atom (which is heavier than
hydrogen), subatomic particles and enormous
release of atomic energy. The attached
picture shows the sequence of the main reaction
at the core of the sun.