Q: Extract the answer to the question from the following context. Question: What is the type of thing that antigens fight against? Context: Resistance to infection (immunity) may be acquired following a disease, by asymptomatic carriage of the pathogen, by harboring an organism with a similar structure (crossreacting), or by vaccination. Knowledge of the protective antigens and specific acquired host immune factors is more complete for primary pathogens than for opportunistic pathogens. There is also the phenomenon of herd immunity which offers a measure of protection to those otherwise vulnerable people when a large enough proportion of the population has acquired immunity from certain infections.
A: pathogen

Q: Extract the answer to the question from the following context. Question: The utilization of stand-alone signs is primarily used by remote country pubs, however, the majority of British pubs also utilize signs, but mainly display them? Context: Most British pubs still have decorated signs hanging over their doors, and these retain their original function of enabling the identification of the pub. Today's pub signs almost always bear the name of the pub, both in words and in pictorial representation. The more remote country pubs often have stand-alone signs directing potential customers to their door.
A: over their doors

Q: Extract the answer to the question from the following context. Question: Who else was affected by the constitutional amendment besides the Soviets? Context: On October 25, 1989, the Supreme Soviet voted to eliminate special seats for the Communist Party and other official organizations in national and local elections, responding to sharp popular criticism that such reserved slots were undemocratic. After vigorous debate, the 542-member Supreme Soviet passed the measure 254-85 (with 36 abstentions). The decision required a constitutional amendment, ratified by the full congress, which met December 1225. It also passed measures that would allow direct elections for presidents of each of the 15 constituent republics. Gorbachev strongly opposed such a move during debate but was defeated.
A: 15 constituent republics

Q: Extract the answer to the question from the following context. Question: How important is lighting to conditions on the battlefield? Context: From a military standpoint, lighting is a critical part of the battlefield conditions. Shadows are good places to hide, while bright areas are more exposed. It is often beneficial to fight with the Sun or other light source behind you, giving your enemy disturbing visual glare and partially hiding your own movements in backlight. If natural light is not present searchlights and flares can be used. However the use of light may disclose your own hidden position and modern warfare have seen increased use of night vision through the use of infrared cameras and image intensifiers.
A:
critical