The following question consists of four sentences on a topic. Some sentences are grammatically incorrect or inappropriate. Select the option that indicates the grammatically correct and appropriate sentences.
- Large reductions in the ozone layer, which sits about $15-30$ km above the earth, take place-each winter over Polar regions, especially the Antarctic, as low temperatures allow the formation of stratospheric clouds that assist chemical reactions breaking down ozone.
- Industrial chemical containing chlorine and bromine have blamed for thinning the layer.
- because they attack the ozone molecules, making them to break apart.
- Many of offending chemicals have been banned.
- It will still take several decades before these substances have disappeared from the atmosphere.
- D only
- B & D
- A & D
- A & C