How many people suffer from lack of knowledge after crossing. How many people carry laptops but face the dilemma of power shortage. How many people bring troops after crossing but only have the logistics of the 19th century. Countless predecessors died on the way of crossing... Countless My seniors fell on the land of another world... Countless seniors became famous but could not return home... Do you still regret not memorizing the formula of glass? Are you still wondering about the composition of gunpowder? Is it perfect and hard to think? In today's world, there are countless colleges and universities working hard for a grant; there are countless research institutions floating in the waves of money; All questions have answers. ... Space-time smuggling group: Group 1: 19486436 (full) Group 2: 64346926 (full) Group 3: 18734339 (new upgrade can be added) Group 4: 18602892 (new group)