Complex sentence: There have been at least eight overseas knock-down factories that produce Great Wall models from knock-down kits: in Egypt, Ethiopia, Indonesia, Iran, Nigeria, Russia, Senegal, Ukraine, Vietnam.
Split into simpler sentences: There have been at least eight overseas knock-down factories that produce Great Wall models from knock-down kits. Factories exist in Egypt, Ethiopia, Indonesia, Iran, Nigeria, Russia, Senegal, Ukraine, Vietnam.