Many studies on the homeless count the number of people who use what?
A. Public restrooms
B. Section 8 vouchers
C. Homeless shelters
D. Campgrounds

C)

Explanation:

The most common way of measuring homelessness is through so-called 'point-in-time' estimates of people who are sleeping in shelters or on the streets. These are figures that are intended to reflect the number of people who are homeless 'on any given night'.

Many studies on the homeless count the number of people who use homeless shelters.

i'm thinking more like energy

snell's law

refractve index = sin incidence / sin refraction