答案

I will spend money on a park. There are some reasons. Firstly, it’s a solution benefiting the widest variety of citizens, most urgent and necessary. Expenditure on the library indeed will make contributions to people’s life psychologically, but in the long run, while spending on the park will bring instance improvement to our daily life, the physical health. Moreover, it will benefit the environment as a whole. Parks with plenty of trees is acknowledged as a main solution to environment protection in the city and its improvement will thus benefit the living surroundings.