hole in ozone layer, decrease in the ozone layer in troposphere, decrease in thickness of ozone layer in stratosphere, increase in the thickness of ozone layer in troposphere" />
hole in ozone layer, decrease in the ozone layer in troposphere, decrease in thickness of ozone layer in stratosphere, increase in the thickness of ozone layer in troposphere" />
hole in ozone layer, decrease in the ozone layer in troposphere, decrease in thickness of ozone layer in stratosphere, increase in the thickness of ozone layer in troposphere" />
