Input: Infection
Persistent infections occur because the body is unable to clear the organism after the initial infection. Persistent infections are characterized by the continual presence of the infectious organism, often as latent infection with occasional recurrent relapses of active infection. There are some viruses that can maintain a persistent infection by infecting different cells of the body. Some viruses once acquired never leave the body. A typical example is the herpes virus, which tends to hide in nerves and become reactivated when specific circumstances arise.

What never leave the body when acquired?
Output: Some viruses


Input: Article: Tracks of the Northern Pacific Railroad (NPR) reached Montana from the west in 1881 and from the east in 1882. However, the railroad played a major role in sparking tensions with Native American tribes in the 1870s. Jay Cooke, the NPR president launched major surveys into the Yellowstone valley in 1871, 1872 and 1873 which were challenged forcefully by the Sioux under chief Sitting Bull. These clashes, in part, contributed to the Panic of 1873 which delayed construction of the railroad into Montana. Surveys in 1874, 1875 and 1876 helped spark the Great Sioux War of 1876. The transcontinental NPR was completed on September 8, 1883, at Gold Creek.

Now answer this question: What years were the railroad challenged by Chief Sitting Bull?

Output: 1871, 1872 and 1873


Article: Humans would also have derived enormous benefit from the dogs associated with their camps. For instance, dogs would have improved sanitation by cleaning up food scraps. Dogs may have provided warmth, as referred to in the Australian Aboriginal expression "three dog night" (an exceptionally cold night), and they would have alerted the camp to the presence of predators or strangers, using their acute hearing to provide an early warning.

Question: What did a dog's good hearing help humans with?
Ans: early warning.


Here is a question about this article: In addition to the Vedas, the principal texts of Hinduism, the core themes of the Sanskrit epics Ramayana and Mahabharata are said to have their ultimate origins during this period. The Mahabharata remains, today, the longest single poem in the world. Historians formerly postulated an "epic age" as the milieu of these two epic poems, but now recognize that the texts (which are both familiar with each other) went through multiple stages of development over centuries. For instance, the Mahabharata may have been based on a small-scale conflict (possibly about 1000 BCE) which was eventually "transformed into a gigantic epic war by bards and poets". There is no conclusive proof from archaeology as to whether the specific events of the Mahabharat have any historical basis. The existing texts of these epics are believed to belong to the post-Vedic age, between c. 400 BCE and 400 CE. Some even attempted to date the events using methods of archaeoastronomy which have produced, depending on which passages are chosen and how they are interpreted, estimated dates ranging up to mid 2nd millennium BCE.
What is the answer to this question: What were the core epics of the Vedas?
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So... Ramayana and Mahabharata


The problem: Answer a question about this article:
Backup and Restore, the backup component of Windows, is deprecated. It still ships with Windows 8 and continues to work on preset schedules, but is pushed to the background and can only be accessed through a Control Panel applet called "Windows 7 File Recovery".:76 Shadow Copy, a component of Windows Explorer that once saved previous versions of changed files, no longer protects local files and folders. It can only access previous versions of shared files stored on a Windows Server computer.:74 The subsystem on which these components worked, however, is still available for other software to use.:74
What does :76 Shadow Copy do?
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The answer: access previous versions of shared files stored on a Windows Server computer


The problem: Answer a question about this article:
Simultaneous videoconferencing among three or more remote points is possible by means of a Multipoint Control Unit (MCU). This is a bridge that interconnects calls from several sources (in a similar way to the audio conference call). All parties call the MCU, or the MCU can also call the parties which are going to participate, in sequence. There are MCU bridges for IP and ISDN-based videoconferencing. There are MCUs which are pure software, and others which are a combination of hardware and software. An MCU is characterised according to the number of simultaneous calls it can handle, its ability to conduct transposing of data rates and protocols, and features such as Continuous Presence, in which multiple parties can be seen on-screen at once. MCUs can be stand-alone hardware devices, or they can be embedded into dedicated videoconferencing units.
In what way can an MCU be characterized?
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The answer:
the number of simultaneous calls it can handle