You should include the terms, or add a picture!
<span>carbon dioxide(CO2) is recycled. In photosynthesis oxygen is recycled.</span>
Motion/direction is determined by an arrow
<span>Certain stretching techniques increase blood flow to
your muscles, while other techniques actually restrict blood flow. Stretching
may seem a little not essential. This activity can make more athletic
performance and decrease your risk of injury. Yet, not all stretches are
created equal. </span>
The answer to this question would be: limbic system
Limbic system is part of the brain that responsible for emotion. One of this part is the olfactory bulb where the smells are processed. That is why a smell of something might make someone remember some memories that were related to the emotion.
In some organism, smells is important for survivability. Smelling a predator might cause the organism to feel fear and run away from them before they got close.
