* Suspensions: These are mixtures where particles are large enough to be seen and will settle out over time. They are not evenly mixed and cannot be easily separated by filtering due to the size of the particles. Think of muddy water – the mud particles will eventually settle to the bottom.

Let's look at the other options:

* Alloys: These are mixtures of metals, usually created by melting and mixing them together. They are often evenly mixed and difficult to separate.

* Colloids: These are mixtures with particles that are larger than those in solutions but smaller than those in suspensions. They are evenly mixed and don't settle out, but they can be difficult to separate. Think of milk or fog.

* Solutions: These are mixtures where one substance (the solute) dissolves completely into another (the solvent). They are evenly mixed and cannot be separated by filtering. Think of salt dissolved in water.