C577 I Can't Save both of Them

Su Wan said, "It's actually very simple. One person fell from the left side of the bridge while the other fell from the right side of the bridge. At this time, you just need to see which side of the river flows and which side is downstream to save. "

Hee Xiaoyu asked, "Why?"

Su Wan smiled and said, "Isn't it simple? Because after the one upstream fell