In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
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Question: Waves contain?, Context: As an electro-magnetic wave travels through the different parts of the antenna system (radio, feed line, antenna, free space) it may encounter differences in impedance (E/H, V/I, etc.). At each interface, depending on the impedance match, some fraction of the wave's energy will reflect back to the source, forming a standing wave in the feed line. The ratio of maximum power to minimum power in the wave can be measured and is called the standing wave ratio (SWR). A SWR of 1:1 is ideal. A SWR of 1.5:1 is considered to be marginally acceptable in low power applications where power loss is more critical, although an SWR as high as 6:1 may still be usable with the right equipment. Minimizing impedance differences at each interface (impedance matching) will reduce SWR and maximize power transfer through each part of the antenna system.

Answer: power


Question: How did the guns function?, Context: After the Dambusters raid in 1943 an entirely new system was developed that was required to knock down any low-flying aircraft with a single hit. The first attempt to produce such a system used a 50 mm gun, but this proved inaccurate and a new 55 mm gun replaced it. The system used a centralised control system including both search and targeting radar, which calculated the aim point for the guns after considering windage and ballistics, and then sent electrical commands to the guns, which used hydraulics to point themselves at high speeds. Operators simply fed the guns and selected the targets. This system, modern even by today's standards, was in late development when the war ended.

Answer: a centralised control system


Question: What are some of GE's competitors?, Context: Since over half of GE's revenue is derived from financial services, it is arguably a financial company with a manufacturing arm. It is also one of the largest lenders in countries other than the United States, such as Japan. Even though the first wave of conglomerates (such as ITT Corporation, Ling-Temco-Vought, Tenneco, etc.) fell by the wayside by the mid-1980s, in the late 1990s, another wave (consisting of Westinghouse, Tyco, and others) tried and failed to emulate GE's success.[citation needed]

Answer:
Westinghouse, Tyco, and others