When a person sees a doctor about a respiratory illness, the doctor will want to determine if the sickness is in the upper respiratory tract or the lower respiratory tract. The starting point for the lower respiratory system is the trachea.

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the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.