In 1995, the FUF set up a program called Tree Care.
1995年，“城市森林之友”（FUF）设立了一个名为“爱护树木”的项目。
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For example, if you write a program that allocates and frees many tree nodes, you might decide that is worth it to cache some nodes, assuming you know of a fast way to do this.
On the other hand, you would store the location of a program in the system tree, as that location is the same for all users and is potentially useful to all users.