What is the common difference of this arithmetic sequence?

He found a victim who had been strangled.

He was strangled by the criminal.

I am grateful for his kind thought.

The Later Tang was a dynasty that existed from 923 to 937.

He had to change schools due to his family's circumstances.

All members of our team are experts.

I can't understand his likes and dislikes.

The statute of limitations has already expired for that case.

There is a math quiz tomorrow.