Final answer:
Streams, till, tributaries, and fully streams are different features of erosion. Streams are flowing bodies of water formed from runoff accumulation, till is sediment deposited by glaciers, tributaries are smaller streams that flow into larger ones, and fully streams are channels created by runoff.
Step-by-step explanation:
The feature 'a' is classified as a stream. Streams are flowing bodies of water that form from the accumulation of runoff. They can be large or small and are an important part of a river system.
The feature 'b' is classified as till. Till is a type of sediment that is deposited by glaciers. It consists of a mixture of rocks, sand, and clay and is commonly found in areas that were once covered by ice.
The feature 'c' is classified as a tributary. A tributary is a smaller stream or river that flows into a larger stream or river. Tributaries play a crucial role in the formation and maintenance of river systems.
The feature 'd' is classified as a fully stream. A fully stream refers to a channel of connected grooves created by runoff. It is a common feature found in environments with high levels of precipitation or where water flows rapidly over the surface of the land.