He works at the switchboard.

We wrote essays for peer grading.

We write in the exchange diary every day.

In mathematics, the commutative law applies to addition and multiplication.

Let's exchange keys tomorrow.

We exchanged our old books for new ones through barter.

Information retrieval technology is essential for finding necessary information from a large amount of data.

Have you ever been to Ufa?

She used to be a prostitute, but now she has started a new life.

My deceased father always encouraged me.