The observation that the front limbs of birds and reptiles have similar homologous structures supports which of the following

Both of these orginsims evolved form a common ancestor

Explanation:

Think about it,  birds evolved from dinosaurs which were reptiles and some dinosauers had feathers and could fly, therefore these two orginisms share a similar ancestor

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.

yes it is   dangerous

explanation:

because that foot is discusting and could get you sick