Try to model a simple Library system that has a number of shelves, and each shelf has a number of books that are arranged in a sorted orderbased on their title.
试着建立一个拥有一定数量书架的简单图书馆系统的模型,每一个书架拥有一些按其名字排序的书籍。
2
Air travel still relies on a ground-based tracking system from the 1950s, which forces planes to use inefficient routes in order to stay in contact with controllers.