There are many different file extensions for documents, such as .docx, .pdf, and .txt.

I did five sets of leg extensions at the gym.

Many universities offer university extensions to provide additional educational opportunities.

Kan extensions are an important concept in category theory.

Conservative extensions are important in logic.

The convergent extensions of the cells were observed under the microscope.

The demarc extensions were installed to expand the network coverage.

I bought some hair extensions for the party.

I need to buy new tiller extensions for my sailboat.

Field extensions are important in abstract algebra.