In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Ex Input:
What is one example of hydrogen cations?, Context: To avoid the implication of the naked "solvated proton" in solution, acidic aqueous solutions are sometimes considered to contain a less unlikely fictitious species, termed the "hydronium ion" (H3O+). However, even in this case, such solvated hydrogen cations are more realistically conceived as being organized into clusters that form species closer to H9O+4. Other oxonium ions are found when water is in acidic solution with other solvents.

Ex Output:
hydronium ion


Ex Input:
What is a part of capacitor?, Context: The maximum energy is a function of dielectric volume, permittivity, and dielectric strength. Changing the plate area and the separation between the plates while maintaining the same volume causes no change of the maximum amount of energy that the capacitor can store, so long as the distance between plates remains much smaller than both the length and width of the plates. In addition, these equations assume that the electric field is entirely concentrated in the dielectric between the plates. In reality there are fringing fields outside the dielectric, for example between the sides of the capacitor plates, which will increase the effective capacitance of the capacitor. This is sometimes called parasitic capacitance. For some simple capacitor geometries this additional capacitance term can be calculated analytically. It becomes negligibly small when the ratios of plate width to separation and length to separation are large.

Ex Output:
plates


Ex Input:
What era was Tamari Ostia from?, Context: Upper Palaeolithic deposits, including bones of Homo sapiens, have been found in local caves, and artefacts dating from the Bronze Age to the Middle Iron Age have been found at Mount Batten showing that it was one of the main trading ports of the country at that time. An unidentified settlement named 'TAMARI OSTIA' (mouth/estuaries of the Tamar) is listed in Ptolemy's Geographia and is presumed to be located in the area of the modern city.

Ex Output:
Ptolemy