I think we should take care of the environment, so that we have something to leave for our children.
我觉得我们应该保护好自然,以便将来能给我们的子孙后代留下一些东西。
Bison waste no longer fell on the ground to improve the soil, which as a result became less good for growing plants.
地上不再有野牛的粪便来改良土壤,结果对于植物生长土壤变得不够肥沃了。