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Bern is built on very uneven ground. There is an elevation difference of several metres between the inner city districts on the Aare (Matte, Marzili) and the higher ones (Kirchenfeld, Länggasse).
What is the elevation difference between the inner cities and the other cities?
A: several metres

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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.
When should the ground crew be done removing luggage?
A: unanswerable

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Programmes, such as the politically fuelled Give My Head Peace (produced by BBC Northern Ireland) and the soap opera River City (produced by BBC Scotland), have been created specifically to cater for some viewers in their respective nations, who may have found programmes created for English audiences irrelevant. BBC Scotland produces daily programmes for its Gaelic-speaking viewers, including current affairs, political and children's programming such as the popular Eòrpa and Dè a-nis?. BBC Wales also produces a large amount of Welsh language programming for S4C, particularly news, sport and other programmes, especially the soap opera Pobol y Cwm ('People of the Valley'). The UK nations also produce a number of programmes that are shown across the UK, such as BBC Scotland's comedy series Chewin' the Fat, and BBC Northern Ireland's talk show Patrick Kielty Almost Live.
What popular children's show does BBC Wales produce for its Gaelic-speaking viewers?
A: unanswerable

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There are generally four recognized levels of tests: unit testing, integration testing, component interface testing, and system testing. Tests are frequently grouped by where they are added in the software development process, or by the level of specificity of the test. The main levels during the development process as defined by the SWEBOK guide are unit-, integration-, and system testing that are distinguished by the test target without implying a specific process model. Other test levels are classified by the testing objective.
What are the other levels classified by?
A:
the testing objective