Global Cataclysm: My Shelter Can Be Infinitely Upgraded

"Thank you for the invitation. In the last days of man's life, the shelter area has covered the whole world." Due to bad luck, he experienced an apocalypse not long after time travel. Shen Lang thought he could lead mankind to survive to the end, but it turned out that the natural disasters and man-made disasters were too severe. However, on the day when all human beings rushed to the streets, Shen Lang was suddenly reborn. What to do before the apocalypse comes? Of course, sell all your belongings to stock up on supplies! This time God obviously favored him and gave him a shelter that could be infinitely upgraded and expanded? Then set a small goal first and try to save all mankind. The introduction is weak, please read the text. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.