A homogeneous mixture is not considered a pure substance because it can be separated through mechanical and thermal processes. A pure substance, however, cannot be separated.<span>
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The answer would be the cell wall or the cell membrane
Where’s the article?
I can’t tell what it’s about from the answers
Most organisms rely on the sun as a primary source of energy
The porcupine is a rodent with an unusual trait. Porcupines have sharp spines or quills that help protect it against its predators. This trait is different from other rodents because of its needle like quills. This animal is also similar to that of a hedgehogs.