Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.

Example Input: Passage: The study also found that there were two previously unknown but related clades (genetic branches) of the Y. pestis genome associated with medieval mass graves. These clades (which are thought to be extinct) were found to be ancestral to modern isolates of the modern Y. pestis strains Y. p. orientalis and Y. p. medievalis, suggesting the plague may have entered Europe in two waves. Surveys of plague pit remains in France and England indicate the first variant entered Europe through the port of Marseille around November 1347 and spread through France over the next two years, eventually reaching England in the spring of 1349, where it spread through the country in three epidemics. Surveys of plague pit remains from the Dutch town of Bergen op Zoom showed the Y. pestis genotype responsible for the pandemic that spread through the Low Countries from 1350 differed from that found in Britain and France, implying Bergen op Zoom (and possibly other parts of the southern Netherlands) was not directly infected from England or France in 1349 and suggesting a second wave of plague, different from those in Britain and France, may have been carried to the Low Countries from Norway, the Hanseatic cities or another site. Question: What do the strains of y. pestis suggest abut the plague?
Example Output: the plague may have entered Europe in two waves

Example Input: Passage: As in the House of Commons, a number of qualifications apply to being an MSP. Such qualifications were introduced under the House of Commons Disqualification Act 1975 and the British Nationality Act 1981. Specifically, members must be over the age of 18 and must be a citizen of the United Kingdom, the Republic of Ireland, one of the countries in the Commonwealth of Nations, a citizen of a British overseas territory, or a European Union citizen resident in the UK. Members of the police and the armed forces are disqualified from sitting in the Scottish Parliament as elected MSPs, and similarly, civil servants and members of foreign legislatures are disqualified. An individual may not sit in the Scottish Parliament if he or she is judged to be insane under the terms of the Mental Health (Care and Treatment) (Scotland) Act 2003. Question: Members of which organizations are disqualified from sitting in the SP as elected MSPs?
Example Output: police and the armed forces

Example Input: Passage: BSkyB's standard definition broadcasts are in DVB-compliant MPEG-2, with the Sky Movies and Sky Box Office channels including optional Dolby Digital soundtracks for recent films, although these are only accessible with a Sky+ box. Sky+ HD material is broadcast using MPEG-4 and most of the HD material uses the DVB-S2 standard. Interactive services and 7-day EPG use the proprietary OpenTV system, with set-top boxes including modems for a return path. Sky News, amongst other channels, provides a pseudo-video on demand interactive service by broadcasting looping video streams. Question: What is the proprietary system that Sky+HD uses?
Example Output:
OpenTV