The pollutants in 1970 were the highest since recorded history and are declining steadily.
Active transport requires energy because it moves molecules across a membrane to a region of lower to higher concentration which is often against their concentration gradient or has an obstructing factor.
Answer:
Publishing results of research projects in peer-reviewed journals enables the scientific and medical community to evaluate the findings themselves. It also provides instructions so that other researchers can repeat the experiment or build on it to verify and confirm the results.
Explanation:
