He is working on a short-term contract.

He is a true patriot, always working hard for the country.

In the Japanese class, the teacher taught us how to use the imperative form.

He performed a low bow to the emperor.

He made a low bow in front of the emperor.

An imaginary unit is an important concept in mathematics.

An astronomical unit represents the average distance from the Earth to the Sun.

This product has a very small assembly unit.

An identity matrix is a square matrix in which all the elements on the diagonal are 1 and all other elements are 0.

He has a very passive personality.