Please help! I will give x Why was 1990 an important year regarding air quality?

The United States took first steps to keep the air clean.
The United States created the Environmental Protection Agency.
Modifications and improvements were made to the Clean Air Act.
Funding was established under the Clean Air Act to study air pollution.

Several bird species feed in a certain species of tree. each bird species feeds in a different part of the tree. which statement is true of these bird species? a. they have adapted to different niches due to competition b. they have a carnivorous relationship with the tree species. c. they have adapted to different niches due to predation d. they have a symbiotic relationship with the tree species.

There are multiple lines of evidence that provide support for common ancestry and evolution. write 3-4 paragraphs describing at least three of them in detail. provide at least one example for each line of evidence.

Which u.s. state lists the horned toad as its state reptile?