4 FS + 16 equal to 13 ​

no but i do not usually comment or use my voice that much when it comes to social media

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.