Many ground crew at the airport work at the aircraft. A tow tractor pulls the aircraft to one of the airbridges, The ground power unit is plugged in. It keeps the electricity running in the plane when it stands at the terminal. The engines are not working, therefore they do not generate the electricity, as they do in flight. The passengers disembark using the airbridge. Mobile stairs can give the ground crew more access to the aircraft's cabin. There is a cleaning service to clean the aircraft after the aircraft lands. Flight catering provides the food and drinks on flights. A toilet waste truck removes the human waste from the tank which holds the waste from the toilets in the aircraft. A water truck fills the water tanks of the aircraft. A fuel transfer vehicle transfers aviation fuel from fuel tanks underground, to the aircraft tanks. A tractor and its dollies bring in luggage from the terminal to the aircraft. They also carry luggage to the terminal if the aircraft has landed, and is being unloaded. Hi-loaders lift the heavy luggage containers to the gate of the cargo hold. The ground crew push the luggage containers into the hold. If it has landed, they rise, the ground crew push the luggage container on the hi-loader, which carries it down. The luggage container is then pushed on one of the tractors dollies. The conveyor, which is a conveyor belt on a truck, brings in the awkwardly shaped, or late luggage. The airbridge is used again by the new passengers to embark the aircraft. The tow tractor pushes the aircraft away from the terminal to a taxi area. The aircraft should be off of the airport and in the air in 90 minutes. The airport charges the airline for the time the aircraft spends at the airport.
What pulls the aircraft to one of the airbridges?
tow tractor

The National Council on Qualifications for the Lighting Professions (NCQLP) offers the Lighting Certification Examination which tests rudimentary lighting design principles. Individuals who pass this exam become 'Lighting Certified' and may append the abbreviation LC to their name. This certification process is one of three national (U.S.) examinations (the others are CLEP and CLMC) in the lighting industry and is open not only to designers, but to lighting equipment manufacturers, electric utility employees, etc.
What other national examinations are available?
CLEP and CLMC

There were 46,917 households, out of which 7,835 (16.7%) had children under the age of 18 living in them, 13,092 (27.9%) were opposite-sex married couples living together, 3,510 (7.5%) had a female householder with no husband present, 1,327 (2.8%) had a male householder with no wife present. There were 2,867 (6.1%) unmarried opposite-sex partnerships, and 416 (0.9%) same-sex married couples or partnerships. 22,716 households (48.4%) were made up of individuals and 5,551 (11.8%) had someone living alone who was 65 years of age or older. The average household size was 1.87. There were 17,929 families (38.2% of all households); the average family size was 2.79.
What percent of households had someone over 65 living in it?
11.8%