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 antibody is a protein (also called an immunoglobulin) that is manufactured by lymphocytes (a type of white blood cell) to neutralize an antigen or foreign protein. Bacteria, viruses and other microorganisms commonly contain many antigens, as do pollens, dust mites, molds, foods, and other substances.