TASK DEFINITION: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
PROBLEM: The most heat-treatable alloys are decided but only?, Context: Conversely, most heat-treatable alloys are precipitation hardening alloys, which produce the opposite effects that steel does. When heated to form a solution and then cooled quickly, these alloys become much softer than normal, during the diffusionless transformation, and then harden as they age. The solutes in these alloys will precipitate over time, forming intermetallic phases, which are difficult to discern from the base metal. Unlike steel, in which the solid solution separates to form different crystal phases, precipitation hardening alloys separate to form different phases within the same crystal. These intermetallic alloys appear homogeneous in crystal structure, but tend to behave heterogeneous, becoming hard and somewhat brittle.

SOLUTION: Conversely

PROBLEM: Which of the following did not occur in the 20th century: urbanization, the spread of the Ottoman Empire, or wars?, Context: South Slavic historically formed a dialect continuum, i.e. each dialect has some similarities with the neighboring one, and differences grow with distance. However, migrations from the 16th to 18th centuries resulting from the spread of Ottoman Empire on the Balkans have caused large-scale population displacement that broke the dialect continuum into many geographical pockets. Migrations in the 20th century, primarily caused by urbanization and wars, also contributed to the reduction of dialectal differences.

SOLUTION: spread of Ottoman Empire

PROBLEM: Which of the following is not an ancient language: Proto-Celtic, Galicia or Proto-Indo-European?, Context: Although the etymology of the name has been studied since the 7th century by authors like Isidore of Seville —who wrote that "Galicians are called so, because of their fair skin, as the Gauls", relating the name to the Greek word for milk—, currently scholars derive the name of the ancient Callaeci either from Proto-Indo-European *kal-n-eH2 'hill', through a local relational suffix -aik-, so meaning 'the hill (people)'; or either from Proto-Celtic *kallī- 'forest', so meaning 'the forest (people)'. In any case, Galicia, being per se a derivation of the ethnic name Kallaikói, would mean 'the land of the Galicians'.

SOLUTION:
Galicia