Identify Grammatically Correct Sentences
Each of the questions consists of a certain number of sentences. Some sentences are grammatically incorrect or inappropriate. Select the option that indicates the grammatically correct and appropriate sentence(s).
- Large reductions in the ozone layer, which sits about 15-30 km above the Earth, take place each winter over the Polar regions, especially the Antarctic, as low temperatures allow the formation of stratospheric clouds that assist chemical reactions breaking down ozone.
- Industrial chemicals containing chlorine and bromine have been blamed for thinning the layer because they attack the ozone molecules, making them to break apart.
- Many an offending chemicals have now been banned.
- It will still take several decades before these substances have disappeared from the atmosphere.