Answer:Why do classification systems change over time? When scientist find new species that may have to change classification systems in order to accommodate them. DNA sequencing has also let us find out more about evolutionary relationships. ... This means that scientists have to change the way they classify them.
Explanation:
<span>You should not be driving if you are experiencing symptoms of drowsiness such a the inability to keep your eyes open, feeling like your eyelids are unusually heavy, frequently blinking or rubbing your eyes or the feeling that they are dryer than normal, if you have trouble remembering or keeping your focus especially of how long you've been driving or how much further you have left to go, yawning, drifting between lanes, and physically slumping your head or body.</span>
Chronic, low-grade depressed feelings are to "dysthymic" disorder as moderate, recurring mood swings are to "<span>cyclothymic"</span> disorder.
Dysthymic disorder is a genuine condition of interminable discouragement, which holds on for no less than two years (one year for youngsters and youths). Dysthymia is less intense and serious than significant depressive issue.
In cyclothymic disorder, temperaments swing between brief times of mellow wretchedness and hypomania, a raised disposition. The low and high emotional episodes never achieve the seriousness or length of significant depressive or full insanity scenes.