Category: Lists of three-character combinations The M40 Field Protective Mask is used by the United States Military and its Allies to protect from field concentrations of chemical and biological agents, along with radiological fallout particles. ... A gas mask, also known as a respirator, is a mask worn on the face to protect the body from airborne pollutants and toxic materials. ... Caliber: 7. ... To meet Wikipedias quality standards, the remainder of this article may require cleanup. ... The M40 Gun Motor Carriage was a US self propelled artillery vehicle that was introduced at the end of the Second World War. ... A self-propelled gun is an armored fighting vehicle which primarily based on and serves to transport the gun with which its equipped. ... The M40 in Warwickshire The M40 motorway is the second motorway in the British transport network to connect London to Birmingham. ... The BMW M40 is an I4 piston engine. ... Components of a typical, four stroke cycle, DOHC piston engine. ... Winnecke 4 (also known as Messier Object 40 or WNC 4) is a double star in the constellation Ursa Major. ... Table of all 110 Messier objects. ... Double Star is a science fiction novel by Robert A. Heinlein. ... Ursa Major (Ursa Maior in Latin) is a constellation visible throughout the year in the northern hemisphere. ... It has been suggested that Apocopation be merged into this article or section. ... Acronyms and initialisms are abbreviations formed from the initial letter or letters of words, such as NATO and XHTML, and are pronounced in a way that is distinct from the full pronunciation of what the letters stand for. ... Acronyms and initialisms are abbreviations formed from the initial letter or letters of words, such as NATO and XHTML, and are pronounced in a way that is distinct from the full pronunciation of what the letters stand for. ... Most three-letter English words are only one syllable long; however, there are certain exceptions such as emu and era. ...