Q: Answer the question

Biotic forces can cause changes to the surface of Earth. Which is the best example of living organisms causing weathering?
OPTIONS:
- Beavers building a dam across a stream.
- Cattle walking and grazing in a grassland.
- Salmon making nests for their eggs in a stream.
- Tree seedlings growing and forming cracks in rocks.

A: Tree seedlings growing and forming cracks in rocks.

Q: Answer the question

The smallest part of an element that retains the properties of the element is the
OPTIONS:
- proton.
- nucleus.
- electron.
- atom.

A: atom.

Q: Answer the question

Visible light is which type of wave?
OPTIONS:
- seismic
- mechanical
- longitudinal
- electromagnetic

A:
electromagnetic