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.

Q: Roofs are traditionally constructed from Alpine rocks such as pieces of schist, gneiss or slate. Such chalets are typically found in the higher parts of the valleys, as in the Maurienne valley in Savoy, where the amount of snow during the cold months is important. The inclination of the roof cannot exceed 40%, allowing the snow to stay on top, thereby functioning as insulation from the cold. In the lower areas where the forests are widespread, wooden tiles are traditionally used. Commonly made of Norway spruce, they are called "tavaillon". The Alpine regions are multicultural and linguistically diverse. Dialects are common, and vary from valley to valley and region to region. In the Slavic Alps alone 19 dialects have been identified. Some of the French dialects spoken in the French, Swiss and Italian alps of Aosta Valley derive from Arpitan, while the southern part of the western range is related to Old Provencal; the German dialects derive from Germanic tribal languages. Romansh, spoken by two percent of the population in southeast Switzerland, is an ancient Rhaeto-Romanic language derived from Latin, remnants of ancient Celtic languages and perhaps Etruscan.

A: What are roofs traditionally constructed from?
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Q: In cpDNA, there are several A G deamination gradients. DNA becomes susceptible to deamination events when it is single stranded. When replication forks form, the strand not being copied is single stranded, and thus at risk for A G deamination. Therefore, gradients in deamination indicate that replication forks were most likely present and the direction that they initially opened (the highest gradient is most likely nearest the start site because it was single stranded for the longest amount of time). This mechanism is still the leading theory today; however, a second theory suggests that most cpDNA is actually linear and replicates through homologous recombination. It further contends that only a minority of the genetic material is kept in circular chromosomes while the rest is in branched, linear, or other complex structures.

A: What kind of gradients does cpDNA have?
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Q: French Huguenot explorer Jean Ribault charted the St. Johns River in 1562 calling it the River of May because he discovered it in May. Ribault erected a stone column near present-day Jacksonville claiming the newly discovered land for France. In 1564, Rene Goulaine de Laudonniere established the first European settlement, Fort Caroline, on the St. Johns near the main village of the Saturiwa. Philip II of Spain ordered Pedro Menendez de Aviles to protect the interest of Spain by attacking the French presence at Fort Caroline. On September 20, 1565, a Spanish force from the nearby Spanish settlement of St. Augustine attacked Fort Caroline, and killed nearly all the French soldiers defending it. The Spanish renamed the fort San Mateo, and following the ejection of the French, St. Augustine's position as the most important settlement in Florida was solidified. The location of Fort Caroline is subject to debate but a reconstruction of the fort was established on the St. Johns River in 1964.

A:
Who mapped the St. Johns River in 1562?
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