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 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 Donauworth on the 17th to find the Grande Armee 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 Eckmuhl. The French scored a convincing win in the resulting Battle of Eckmuhl, 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?

Though much of Enlightenment political thought was dominated by social contract theorists, both David Hume and Adam Ferguson criticized this camp. Hume's essay Of the Original Contract argues that governments derived from consent are rarely seen, and civil government is grounded in a ruler's habitual authority and force. It is precisely because of the ruler's authority over-and-against the subject, that the subject tacitly consents; Hume says that the subjects would "never imagine that their consent made him sovereign", rather the authority did so. Similarly, Ferguson did not believe citizens built the state, rather polities grew out of social development. In his 1767 An Essay on the History of Civil Society, Ferguson uses the four stages of progress, a theory that was very popular in Scotland at the time, to explain how humans advance from a hunting and gathering society to a commercial and civil society without "signing" a social contract.
In what work did Ferguson explain how humans advanced from a hunting and gathering society to a commercial and civil society without "signing" a social contract?

Bell and his partners, Hubbard and Sanders, offered to sell the patent outright to Western Union for $100,000. The president of Western Union balked, countering that the telephone was nothing but a toy. Two years later, he told colleagues that if he could get the patent for $25 million he would consider it a bargain. By then, the Bell company no longer wanted to sell the patent. Bell's investors would become millionaires, while he fared well from residuals and at one point had assets of nearly one million dollars.
How much did Bell et al. try to sell his patent for?