instruction:
This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
question:
The city remained in the hands of Christian troops until 1102, when the Almoravids retook the city and restored the Muslim religion. Although the self-styled 'Emperor of All Spain', Alfonso VI of León and Castile, drove them from the city, he was not strong enough to hold it. The Christians set it afire before abandoning it, and the Almoravid Masdali took possession on 5 May 1109. The event was commemorated in a poem by Ibn Khafaja in which he thanked Yusuf ibn Tashfin for the city's liberation.The declining power of the Almoravids coincided with the rise of a new dynasty in North Africa, the Almohads, who seized control of the peninsula from the year 1145, although their entry into Valencia was deterred by Ibn Mardanis, King of Valencia and Murcia until 1171, at which time the city finally fell to the North Africans. The two Muslim dynasties would rule Valencia for more than a century.
answer:
In what year did Christian troops lose control of Valencia?


question:
Other 19th-century critics, following Rousseau have accepted this differentiation between higher and lower culture, but have seen the refinement and sophistication of high culture as corrupting and unnatural developments that obscure and distort people's essential nature. These critics considered folk music (as produced by "the folk", i.e., rural, illiterate, peasants) to honestly express a natural way of life, while classical music seemed superficial and decadent. Equally, this view often portrayed indigenous peoples as "noble savages" living authentic and unblemished lives, uncomplicated and uncorrupted by the highly stratified capitalist systems of the West.
answer:
What type of music did critics associate with corrupt high culture?


question:
In the UK, the Medicines and Healthcare Products Regulatory Agency approves drugs for use, though the evaluation is done by the European Medicines Agency, an agency of the European Union based in London. Normally an approval in the UK and other European countries comes later than one in the USA. Then it is the National Institute for Health and Care Excellence (NICE), for England and Wales, who decides if and how the National Health Service (NHS) will allow (in the sense of paying for) their use. The British National Formulary is the core guide for pharmacists and clinicians.
answer:
Who is the core guide?