Input: Article: The year used in dates during the Roman Republic and the Roman Empire was the consular year, which began on the day when consuls first entered office—probably 1 May before 222 BC, 15 March from 222 BC and 1 January from 153 BC. The Julian calendar, which began in 45 BC, continued to use 1 January as the first day of the new year. Even though the year used for dates changed, the civil year always displayed its months in the order January to December from the Roman Republican period until the present.

Now answer this question: When did Rome begin to use the Julian calendar?

Output: 45 BC

Input: Article: Her Diamond Jubilee in 2012 marked 60 years on the throne, and celebrations were held throughout her realms, the wider Commonwealth, and beyond. In a message released on Accession Day, she stated: "In this special year, as I dedicate myself anew to your service, I hope we will all be reminded of the power of togetherness and the convening strength of family, friendship and good neighbourliness ... I hope also that this Jubilee year will be a time to give thanks for the great advances that have been made since 1952 and to look forward to the future with clear head and warm heart". She and her husband undertook an extensive tour of the United Kingdom, while her children and grandchildren embarked on royal tours of other Commonwealth states on her behalf. On 4 June, Jubilee beacons were lit around the world. On 18 December, she became the first British sovereign to attend a peacetime Cabinet meeting since George III in 1781.

Now answer this question: When was the last time that a sovereign attended a peacetime cabinet meeting? 

Output: 1781

Input: Article: The production for sulfidic zinc ores produces large amounts of sulfur dioxide and cadmium vapor. Smelter slag and other residues of process also contain significant amounts of heavy metals. About 1.1 million tonnes of metallic zinc and 130 thousand tonnes of lead were mined and smelted in the Belgian towns of La Calamine and Plombières between 1806 and 1882. The dumps of the past mining operations leach significant amounts of zinc and cadmium, and, as a result, the sediments of the Geul River contain significant amounts of heavy metals. About two thousand years ago emissions of zinc from mining and smelting totaled 10 thousand tonnes a year. After increasing 10-fold from 1850, zinc emissions peaked at 3.4 million tonnes per year in the 1980s and declined to 2.7 million tonnes in the 1990s, although a 2005 study of the Arctic troposphere found that the concentrations there did not reflect the decline. Anthropogenic and natural emissions occur at a ratio of 20 to 1.

Now answer this question: Smelter slag contains a significant amount of what?

Output:
heavy metals