Which two of the following are MAIN ideas of the article? 1. Carbon shifts from one area to others through the slow and fast carbon cycles. 2. When the ocean takes in more carbon than it releases, it becomes more acidic. 3. Rain breaks down rocks, which are eventually brought to the ocean. 4. Human behavior has led to increased carbon levels in the atmosphere.

"a scientist studying a whale and its surroundings would need to understand the structure of atoms in case something was negatively affecting the whale or its surroundings."

explanation:

this was from the link provided:

the second type of galaxy is called a barred spiral, which has a thing called a bar straddling the nucleus

answer increasing the intensity, duration,and frequency of exercise progressively;