21.   The chemicals combined with the stronger sunlight of spring and very low temperatures in the lower stratosphere to destroy ozone, the agency said.

22.   The Antarctic depletion begins in August and hits its low point in October, as chlorine and bromine destroy ozone within high-altitude clouds.

23.   As a direct result of their findings, major decisions have been taken to prohibit the release of gases that destroy ozone.

24.   Such clouds help convert certain forms of chlorine found in the stratosphere into highly reactive compounds, which combined with sunlight destroy ozone.

25.   Thanks to the work done by the three scientists, major decisions have been taken prohibiting the release of gases that destroy ozone.