Acid rain is known to contain some acids. Name these acids and where from they come in rain?

Acid rain contains H2CO3, HNO3 and H2SO4. H2CO3 is formed by the dissolution of CO2 of the air in which the water vapour is present.
CO2+H2OH2CO3 
Forest fire and lightning are the natural source of nitric oxide (NO). Nitrogen oxides are also produced by combustion engines, aircraft, furnaces, incinerators, industrial plants.
Nitric oxide slowly reacts with atmospherica air and produce NO2. NO2 dissolves in water to form HNO3.
3NO2+H2O2HNO3+NO
Sulphur oxides are produced by the burning of fossil fuels and in extraction of metals from their sulphide ores etc. Sulphur dioxide also produces sulphuric acid in the similar way.
SO2+O2+H2OMetal oxideSoot particlesH2SO4+[O]