He spent time on the revision of the thesis.

This equation has a singularity.

The main problem with this project is the lack of communication.

This sentence is using nomaten.

A part alternation mark is used in these lyrics.

I stayed at this hotel for 3 nights.

What is this box used for?

What is in this box?

He urged me to give an answer immediately.

My aunt made me some delicious food.