After Time Travel, I Actually Want to Save History

[No system + reversal + history] Xiao Chen and Zhang Feng, as good friends who love and study history, accidentally met an old man and received ancient coins. After traveling through time, he takes on the important task of saving historical changes. Each historical event node, each touching rescue and restoration. Finally, the two realized that history is like a big river. Although there are waves, it will eventually return to the sea. Everything they do is to keep the river flowing smoothly.