What causes a ducks feathers to repeal water

Ducks have a special gland positioned near their tails, called the preen gland. This gland produces an oil, which ducks rub over their feathers with their beaks to maintain their waterproof effect. This oil creates a protective barrier that stops feathers becoming waterlogged.

what subject is this

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.