6) Two of the greenhouse gases that may be responsible for the increased ice melting in Greenland are A) hydrogen and helium
C) oxygen and silicon
B) carbon dioxide and methane
D) nitrogen and oxygen

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme