Without it, the soldiers would starve and the ship would not be able to move without refueling. When it comes to Russian supply ships, China has a long history. In April 2015, China signed a contract with Russia, under which the Russian navy purchased from China five sets of sea-based replenishment systems for ocean-going integrated supply ships. The news made the eyes of the United States and Europe fall off, because at that time China’s supply ships were very backward, compared with the United States, it was like a child compared to an adult, but nonetheless, Russia is still determined to buy from China, why? Speaking of which, it is the Russian navy’s “gratitude” to China.