Answer:
Tributary, River,River System
Explanation:
Tributary is smaller because it is like a smaller river running into a larger one. River System is largest because this is all of the rivers in one.
As precipitation infiltrates into the subsurface soil, it generally forms an unsaturated zone and a saturated zone. In the unsaturated zone, the voids—that is, the spaces between grains of gravel, sand, silt, clay, and cracks within rocks—contain both air and water. Although a lot of water can be present in the unsaturated zone
Uracil I believe (sorry if it’s wrong)
