Question

Why was 1990 an important year regarding air quality

Answer 1

Answer:

The United States took first steps to keep the air clean. Cost-effective ways to reduce pollution were emphasized. The United States created the environmental protection agency. Hope this helps

Explanation:

Answer 2

Answer:

Why was 1990 an important year regarding air quality? ... The United States took first steps to keep the air clean. Cost-effective ways to reduce pollution were emphasized. The United States created the environmental protection agency

Explanation: