The North Building is an old one, some of stairs are broken.LiuDi steped on the place carefully and watched out for the rampaged boys at the same time.

• 北楼是一座旧楼，楼梯已经有些残破了，柳笛一边小心地选择着落脚的地方，一边提防着那些横冲直撞的男孩子。