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:
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.
answer:
Conversely


question:
Which trade route connected Northern Europe and Northwestern Russia with the Capsian Sea?, Context: The new Kievan state prospered due to its abundant supply of furs, beeswax, honey, and slaves for export, and because it controlled three main trade routes of Eastern Europe. In the north, Novgorod served as a commercial link between the Baltic Sea and the Volga trade route to the lands of the Volga Bulgars, the Khazars, and across the Caspian Sea as far as Baghdad, providing access to markets and products from Central Asia and the Middle East. Trade from the Baltic also moved south on a network of rivers and short portages along the Dnieper known as the "route from the Varangians to the Greeks," continuing to the Black Sea and on to Constantinople. Kiev was a central outpost along the Dnieper route and a hub with the east-west overland trade route between the Khazars and the Germanic lands of Central Europe. These commercial connections enriched Rus' merchants and princes, funding military forces and the construction of churches, palaces, fortifications, and further towns. Demand for luxury goods fostered production of expensive jewelry and religious wares, allowing their export, and an advanced credit and money-lending system may have also been in place.
answer:
Volga trade route


question:
What is fundamental to the function of the airport that has yet to be obtained?, Context: The UK government has spent £250 million in the construction of the island's airport. Expected to be fully operational early 2016, it is expected to help the island towards self-sufficiency and encourage economic development, reducing dependence on British government aid. The airport is also expected to kick start the tourism industry, with up to 30,000 visitors expected annually. As of August, 2015 ticketing was postponed until an airline could be firmly designated.
answer:

airline