When an engine is ignited, it produces thrust and boosts the rocket into the sky. After the propellant is used up, delay is activated, producing tracking smoke and allowing the rocket a brief coast.
infirmary (plural infirmaries) 1  A place where sick or injured people are cared for, especially a small hospital; sickhouse. 2  A clinic or dispensary within another institution.
An ulcer (/ËÊlsÉr/; from Latin ulcus, ulcer, sore) is a break in the skin or mucous membrane with loss of surface tissue and the disintegration and necrosis of epithelial tissue. A mucosal ulcer is an ulcer which specifically occurs on a mucous membrane.