Question: In 1207, the Mongol ruler Genghis Khan (r. 1206–1227) conquered and subjugated the ethnic Tangut state of the Western Xia (1038–1227). In the same year, he established diplomatic relations with Tibet by sending envoys there. The conquest of the Western Xia alarmed Tibetan rulers, who decided to pay tribute to the Mongols. However, when they ceased to pay tribute after Genghis Khan's death, his successor Ögedei Khan (r. 1229–1241) launched an invasion into Tibet.
Is there an answer to this question: Who was Genghis Khan's successor? 

Answer: Ögedei Khan


Question: The rainfall inhibition and the dissipation of cloud cover are most accentuated over the eastern section of the Sahara rather than the western. The prevailing air mass lying above the Sahara is the continental tropical (cT) air mass which is hot and dry. Hot, dry air masses primarily form over the North-African desert from the heating of the vast continental land area, and it affects the whole desert during most of the year. Because of this extreme heating process, a thermal low is usually noticed near the surface, and is the strongest and the most developed during the summertime. The Sahara High represents the eastern continental extension of the Azores High, centered over the North Atlantic Ocean. The subsidence of the Sahara High nearly reaches the ground during the coolest part of the year while it limits to the upper troposphere during the hottest periods.
Is there an answer to this question: over what region is there the most cloud coverage?

Answer: unanswerable


Question: Following a custom she maintained throughout her widowhood, Victoria spent the Christmas of 1900 at Osborne House on the Isle of Wight. Rheumatism in her legs had rendered her lame, and her eyesight was clouded by cataracts. Through early January, she felt "weak and unwell", and by mid-January she was "drowsy ... dazed, [and] confused". She died on Tuesday, 22 January 1901, at half past six in the evening, at the age of 81. Her son and successor King Edward VII, and her eldest grandson, Emperor Wilhelm II of Germany, were at her deathbed. Her favourite pet Pomeranian, Turri, was laid upon her deathbed as a last request.
Is there an answer to this question: How old was Victoria when she died?

Answer: 81


Question: Moisture absorption occurs when the material is exposed to high humidity or water. Both the resin and the reinforcement may absorb water; water may be also soaked by capillary forces through voids in the materials and along the reinforcement. Epoxies of the FR-4 materials aren't too susceptible, with absorption of only 0.15%. Teflon has very low absorption of 0.01%. Polyimides and cyanate esters, on the other side, suffer from high water absorption. Absorbed water can lead to significant degradation of key parameters; it impairs tracking resistance, breakdown voltage, and dielectric parameters. Relative dielectric constant of water is about 73, compared to about 4 for common circuitboard materials. Absorbed moisture can also vaporize on heating and cause cracking and delamination, the same effect responsible for "popcorning" damage on wet packaging of electronic parts. Careful baking of the substrates may be required.
Is there an answer to this question: What percentage absorption do F-4 epoxies have?

Answer:
0.15%