Electricity consumption is a huge producer of atmospheric carbon dioxide because much of the USA’s electricity is produced in coal burning power plants. What are three other ways that electricity can be produced that would NOT increase the amount of carbon dioxide in the air? Which of these do you think holds the most promise for the future?

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]

the correct answer is 2 and 4