One generation plants the trees, and the next enjoys the shade; meaning that previous generations make efforts or contributions from which future generations benefit.
村里的老人们当年积极修建水利设施，才有了我们现在年年丰收，真是前人种树，后人乘凉啊
The older generations in the village actively built water conservancy facilities, which is why we now enjoy abundant harvests every year. It truly exemplifies 'one generation plants the trees, another enjoys the shade'.
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