Answer:
Knowing that an oasis is a patch or a splash technically of water it could hold a multitude of purposes. It could quench thirst provide a way to farm and many many more things. Water has so many uses and is absolutely needed to satisfy 80% of our bodies being humans. So there is no reason specifically alone on why an oasis would be useful but certainly a couple of the many.
Step-by-step explanation:
I assum this is long enough unless you needed to write an essay for it let me know if I should add!