instruction:
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
question:
What is one example of hydrogen cations?, Context: To avoid the implication of the naked "solvated proton" in solution, acidic aqueous solutions are sometimes considered to contain a less unlikely fictitious species, termed the "hydronium ion" (H3O+). However, even in this case, such solvated hydrogen cations are more realistically conceived as being organized into clusters that form species closer to H9O+4. Other oxonium ions are found when water is in acidic solution with other solvents.
answer:
hydronium ion


question:
What was the name of the person who joined in on the coup with Xianfeng's empress?, Context: These years saw an evolution in the participation of Empress Dowager Cixi (Wade–Giles: Tz'u-Hsi) in state affairs. She entered the imperial palace in the 1850s as a concubine to the Xianfeng Emperor (r. 1850–1861) and came to power in 1861 after her five-year-old son, the Tongzhi Emperor ascended the throne. She, the Empress Dowager Ci'an (who had been Xianfeng's empress), and Prince Gong (a son of the Daoguang Emperor), staged a coup that ousted several regents for the boy emperor. Between 1861 and 1873, she and Ci'an served as regents, choosing the reign title "Tongzhi" (ruling together). Following the emperor's death in 1875, Cixi's nephew, the Guangxu Emperor, took the throne, in violation of the dynastic custom that the new emperor be of the next generation, and another regency began. In the spring of 1881, Ci'an suddenly died, aged only forty-three, leaving Cixi as sole regent.
answer:
Prince Gong


question:
Who escaped with support from X Corps?, Context: On 25 November at the Korean western front, the PVA 13th Army Group attacked and overran the ROK II Corps at the Battle of the Ch'ongch'on River, and then decimated the US 2nd Infantry Division on the UN forces' right flank. The UN Command retreated; the U.S. Eighth Army's retreat (the longest in US Army history) was made possible because of the Turkish Brigade's successful, but very costly, rear-guard delaying action near Kunuri that slowed the PVA attack for two days (27–29 November). On 27 November at the Korean eastern front, a U.S. 7th Infantry Division Regimental Combat Team (3,000 soldiers) and the U.S. 1st Marine Division (12,000–15,000 marines) were unprepared for the PVA 9th Army Group's three-pronged encirclement tactics at the Battle of Chosin Reservoir, but they managed to escape under Air Force and X Corps support fire—albeit with some 15,000 collective casualties.
answer:

a U.S. 7th Infantry Division Regimental Combat Team (3,000 soldiers) and the U.S. 1st Marine Division


