Many problems contain subtleties which were resolved long ago in mainstream engineering (such as the importance of a wheel's rim being smooth).

This is generally light (low-gluten) flour, and occasionally contains leaveners such as baking powder.

Some probiotic products may contain live bacteria (such as bifidobacteria).

This section contained lessons on common vocabulary, such as the names of animals, plants, and types of buildings, in the Narragansett language.

Systems for fine removal may only contain a single filtration system (such as a filter bag or cartridge).

Also, marine fuel oils sometimes contain waste products such as used motor oil.

The second season does not contain any extra features such as deleted scenes.

Assume that your report contained a sentence such as the following.

They often contain other tools in addition to the axe head, such as spikes or hammers.

Hydrolyzed protein contains free amino acids, such as glutamate, at levels of 5% to 20%.