Stimulation of the neurons in the "pleasure pathway" (the site in the brain that seems to be involved inthe experience of pleasure) probably causes the "high" associated with cocaine use.

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

hope this !

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

producers within ecosystems are essential as they are at the base of the food chain. plants are examples of producers. they use the process of photosynthesis to capture light energy and use it to convert simple inorganic substances (carbon dioxide and water) into organic substances (glucose).