This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

[EX Q]: Passage: By August 1805, Napoleon had realized that the strategic situation had changed fundamentally. Facing a potential invasion from his continental enemies, he decided to strike first and turned his army's sights from the English Channel to the Rhine. His basic objective was to destroy the isolated Austrian armies in Southern Germany before their Russian allies could arrive. On 25 September, after great secrecy and feverish marching, 200,000 French troops began to cross the Rhine on a front of 260 km (160 mi). Austrian commander Karl Mack had gathered the greater part of the Austrian army at the fortress of Ulm in Swabia. Napoleon swung his forces to the southeast and the Grande Armée performed an elaborate wheeling movement that outflanked the Austrian positions. The Ulm Maneuver completely surprised General Mack, who belatedly understood that his army had been cut off. After some minor engagements that culminated in the Battle of Ulm, Mack finally surrendered after realizing that there was no way to break out of the French encirclement. For just 2000 French casualties, Napoleon had managed to capture a total of 60,000 Austrian soldiers through his army's rapid marching. The Ulm Campaign is generally regarded as a strategic masterpiece and was influential in the development of the Schlieffen Plan in the late 19th century. For the French, this spectacular victory on land was soured by the decisive victory that the Royal Navy attained at the Battle of Trafalgar on 21 October. After Trafalgar, Britain had total domination of the seas for the duration of the Napoleonic Wars. Question: By August 1805, Napoleon changed the primary target of his army's efforts from the English Channel to what area?
[EX A]: the Rhine

[EX Q]: Passage: At present the A35 autoroute, which parallels the Rhine between Karlsruhe and Basel, and the A4 autoroute, which links Paris with Strasbourg, penetrate close to the centre of the city. The Grand contournement ouest (GCO) project, programmed since 1999, plans to construct a 24 km (15 mi) long highway connection between the junctions of the A4 and the A35 autoroutes in the north and of the A35 and A352 autoroutes in the south. This routes well to the west of the city and is meant to divest a significant portion of motorized traffic from the unité urbaine. Question: How far is the connection between junctions A4 and the A35?
[EX A]: 24 km

[EX Q]: Passage: On 13 December 1904, Hungarian Sándor Just and Croatian Franjo Hanaman were granted a Hungarian patent (No. 34541) for a tungsten filament lamp that lasted longer and gave brighter light than the carbon filament. Tungsten filament lamps were first marketed by the Hungarian company Tungsram in 1904. This type is often called Tungsram-bulbs in many European countries. Filling a bulb with an inert gas such as argon or nitrogen retards the evaporation of the tungsten filament compared to operating it in a vacuum. This allows for greater temperatures and therefore greater efficacy with less reduction in filament life. Question: What type of gas fills a tungsten filament bulb?
[EX A]:
argon or nitrogen