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:
How is a husband referred to?, Context: Knights Grand Cross and Knights Commander prefix Sir, and Dames Grand Cross and Dames Commander prefix Dame, to their forenames.[b] Wives of Knights may prefix Lady to their surnames, but no equivalent privilege exists for husbands of Knights or spouses of Dames. Such forms are not used by peers and princes, except when the names of the former are written out in their fullest forms. Clergy of the Church of England or the Church of Scotland do not use the title Sir or Dame as they do not receive the accolade (i.e., they are not dubbed "knight" with a sword), although they do append the post-nominal letters.
answer:
no equivalent privilege exists for husbands

question:
What is the second distance given in the text in km, Context: The most dense rail network in Europe of 5,063 km (3,146 mi) carries over 350 million passengers annually. In 2007, each Swiss citizen travelled on average 2,258 km (1,403 mi) by rail, which makes them the keenest rail users. The network is administered mainly by the Federal Railways, except in Graubunden, where the 366 km (227 mi) narrow gauge railway is operated by the Rhaetian Railways and includes some World Heritage lines. The building of new railway base tunnels through the Alps is under way to reduce the time of travel between north and south through the AlpTransit project.
answer:
2,258 km

question:
What type of animal creature does the immune system protect against?, Context: The immune system is a system of many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism's own healthy tissue. In many species, the immune system can be classified into subsystems, such as the innate immune system versus the adaptive immune system, or humoral immunity versus cell-mediated immunity. In humans, the bloodbrain barrier, bloodcerebrospinal fluid barrier, and similar fluidbrain barriers separate the peripheral immune system from the neuroimmune system which protects the brain.
answer:
parasitic worms