How would a scientist determine the age of a fossilized dinosaur egg?

How does the molecular clock work? a. it analyzes the brain functionality of two different species.b. it examines and compares the physical characteristics of two different species.c. it illustrates relationships between two different species.d. it compares the number of mutations that exist in the dna of two different species.

The response is the basis for vaccination. primary secondary tertiary none of the above

What percentage of light hits earth's surface directly?