Ключевые слова: 3d, abstract, background, banner, barrier, block, blue, border, border closure, border post, closed, coronavirus, country, covid19, crossing border, customs, danger, dangerous, defense, disease, entry, epidemic, europe, flu, forbidden, hazard, illness, illustration, immigration, infection, isolated, isolation, national border, protect, protection, quarantine, render, rendering, security, state, stop, travel, virus,