Which of the following values represents an index of refraction of an actual material?
a. 0
b. 25
c. 5
d. 1.25

The correct answer is:

D.  1.25

It has to be more than "1"

the "dirty dozen" chemicals banned in an international treaty are formally known as persistent organic pollutants, or pops. the united nations environment program provided this background on what they are and what they can do to humans and wildlife.

i hope this

b.have there own function.