In order to protect aquifers near landfills, material is placed under the soil to prevent pollution. which following property must the protective material possess? a) high porosity b) low permeabilityc) high reflectivityd) low conductivity

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.

answer seismograph;

the answer is symmetrical : )