I think it is c density and temperature
Answer:

Explanation:
P = Acoustic power = 63 µW
r = Distance to the sound source = 210 m
Acoustic power

Threshold intensity = 
Ratio

Ratio of the acoustic intensity produced by the juvenile howler to the reference intensity is 113.68
A convex lens makes light rays converge (come together) at the focal point or focus. The distance from the center of the lens to the focal point is the focal length of the lens. Convex lenses are used in things like telescopes and binoculars to bring distant light rays to a focus in your eyes.
Answer:
Ampere
Explanation:
The ampere is the unit of measurement in the international system. Its equal to a coulomb/second. It can be describe as the rate of charges flowing throught a conductor
The answer to this question is B....hope this helps.