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.

In times past, until the 15th century, in Korea, Literary Chinese was the dominant form of written communication, prior to the creation of hangul, the Korean alphabet. Much of the vocabulary, especially in the realms of science and sociology, comes directly from Chinese, comparable to Latin or Greek root words in European languages. However, due to the lack of tones in Korean,[citation needed] as the words were imported from Chinese, many dissimilar characters took on identical sounds, and subsequently identical spelling in hangul.[citation needed] Chinese characters are sometimes used to this day for either clarification in a practical manner, or to give a distinguished appearance, as knowledge of Chinese characters is considered a high class attribute and an indispensable part of a classical education.[citation needed] It is also observed that the preference for Chinese characters is treated as being conservative and Confucian.
What was the dominant form of written communication?

In the early morning of 10 April, leading elements of the Austrian army crossed the Inn River and invaded Bavaria. The early Austrian attack surprised the French; Napoleon himself was still in Paris when he heard about the invasion. He arrived at Donauwörth on the 17th to find the Grande Armée in a dangerous position, with its two wings separated by 75 miles (121 km) and joined together by a thin cordon of Bavarian troops. Charles pressed the left wing of the French army and hurled his men towards the III Corps of Marshal Davout. In response, Napoleon came up with a plan to cut off the Austrians in the celebrated Landshut Maneuver. He realigned the axis of his army and marched his soldiers towards the town of Eckmühl. The French scored a convincing win in the resulting Battle of Eckmühl, forcing Charles to withdraw his forces over the Danube and into Bohemia. On 13 May, Vienna fell for the second time in four years, although the war continued since most of the Austrian army had survived the initial engagements in Southern Germany.
On what date did the Austrian army first cross the Inn River?

David Archuleta's performance of John Lennon's "Imagine" was considered by many as one of the best of the season. Jennifer Lopez, who was brought in as a judge in season ten, called it a beautiful song-moment that she will never forget. Jason Castro's semi-final performance of "Hallelujah" also received considerable attention, and it propelled Jeff Buckley's version of the song to the top of the Billboard digital song chart. This was the first season in which contestants' recordings were released onto iTunes after their performances, and although sales information was not released so as not to prejudice the contest, leaked information indicated that contestants' songs frequently reached the top of iTunes sales charts.

Which contestant sang "Imagine" on season seven of American Idol?