He researched his family tree to go back through his ancestors' history.

He traced his lineage back many generations.

It is important to find the root of this problem.

The culture of the Korean Peninsula is very unique, and its history dates back to ancient times.

His thought is deep.

The root and trunk of this tree are very strong.

He is an active duty firefighter.

The performance dropped in the second quarter of this year due to a decrease in profits.

Due to the impact of the new coronavirus, our company's profits have decreased.

I bought three fish at the market.