Sinusitis is an inflammation of the sinuses. It is often caused by bacterial (germ) infection. Sometimes, viruses and fungi (molds) cause it. People with weak immune systems are more likely to develop bacterial or fungal sinus infection. Some people with allergies can have allergic fungal sinus infection. Acute sinus infection lasts three to eight weeks. A sinus infection lasting longer than eight weeks is considered chronic.
Define Upper stage. Upper stage synonyms, Upper stage pronunciation, Upper stage translation, English dictionary definition of Upper stage. n. A rocket composed of two or more propulsion units that fire in succession. Also called step rocket . Noun 1. multistage rocket - a rocket having two or...
In Egyptian history, the Upper and Lower Egypt period (also known as The Two Lands, a name for Ancient Egypt during this time) was the final stage of its prehistory and directly preceded the nation's unification.