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

My father runs a warehouse business.

This event is a part of the important functions of the school.

He is a friend as precious as gold and jade.

He proudly showed me his diploma.

In Japanese grammar, verbs with k-row irregular conjugation are characteristic.

Verbs of the sa-line irregular conjugation are a special existence in Japanese.

Verbs of the 'ra-row irregular conjugation' are a special existence in Japanese.

In Japanese grammar, 'n-row irregular conjugation' is a very important concept.

The proprietor is thinking about a new business plan.