Question

Why was 1990 an important year regarding air quality

Answer 1

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

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Answer 2

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

Step-by-step explanation: