How successful has it been in reducing the harmful chemicals from the burning of fossil fuels that cause acid rain?

Not very successful considering the fact that there is still acid rain even with more advances in technology such as the development of hydroelectric power plants and other renewable forms of energy so as to reduce the continuous burning of fossil fuels.

Explanation:

Acid rain is produced when sulfur and nitrogen in their oxide forms are released into the atmosphere where they get to meet with water and other chemicals. Since water contains hydrogen and oxygen, it reacts with sulfur and nitrogen in their oxide form to produce weak acids which come down to the earth as it rains. Fossil fuel combustion is a man-made practice of releasing sulfur and nitrogen in their oxide form into the atmosphere which eventually results in acid rain.

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.