Or the machine of time was invented, but everyone in a row was not allowed to use it, and in the 20-21 centuries in general quarantine, and for attempts to drive there translucidated, this is the same time of mass disturbance, the infection will be brought from there. Or traveling in time requires low costs, and simply by "go for tea" no one ran out to spend an annual salary on electricity.

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You are all so inventive. They are cute in their naivety.

Third World War, and it is the last.
It was quiet, calm and without any inventions.