大小单双公式规律

简介：The Kaifeng city wall is four feet high, which is 12 meters. If you jump directly, you will definitely be injured. However, because there are a large number of reeds on the bottom, no one of the officers and soldiers who jumped from the top of the city was injured. After one of them rolled down from the pile of reeds, Immediately swing his sword to kill the stray thief at the entrance of the cave.