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

What is the last place listed that engaged in the slave trade?, Context: The slave trade was engaged in by European state and non-state actors such as Great Britain, the Netherlands, Portugal and private companies, as well as various African states and non-state actors. With rising anti-slavery sentiment at home and changing economic realities, Great Britain outlawed the international slave trade in 1807. Following the Napoleonic Wars, Great Britain established the West Africa Squadron in an attempt to halt the international traffic in slaves. It stopped ships of other nations that were leaving the African coast with slaves; the seized slaves were taken to Freetown, a colony in West Africa originally established for the resettlement of freed slaves from Britain. Britain intervened in the Lagos Kingship power struggle by bombarding Lagos in 1851, deposing the slave trade friendly Oba Kosoko, helping to install the amenable Oba Akitoye, and signing the Treaty between Great Britain and Lagos on 1 January 1852. Britain annexed Lagos as a Crown Colony in August 1861 with the Lagos Treaty of Cession. British missionaries expanded their operations and travelled further inland. In 1864, Samuel Ajayi Crowther became the first African bishop of the Anglican Church.
various African states

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.
hydronium ion

How many arrivals in the century before 1937?, Context: Sometimes circumstances such as a good breeding season followed by a food source failure the following year lead to irruptions in which large numbers of a species move far beyond the normal range. Bohemian waxwings Bombycilla garrulus well show this unpredictable variation in annual numbers, with five major arrivals in Britain during the nineteenth century, but 18 between the years 1937 and 2000. Red crossbills Loxia curvirostra too are irruptive, with widespread invasions across England noted in 1251, 1593, 1757, and 1791.
five