What is the ph of milk? is it an acid, base, or neutral?

Some sources cite milk as being neutral since it is so close to the neutral  however milk contains lactic acid, which is a hydrogen donor or proton donor.

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.