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 have achieved great success but could not return to their hometowns... Are you still regretting not remembering 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 that are ups and downs in the waves of money; All questions have answers.... Time-space smuggling group: Group 1: 19486436 (full) Group 2: 64346926 (full) Group 3: 18734339 (new upgrade can be added) Group 4: 18602892 (new group)