This economical size shampoo is economical because it can be used for a long period of time.

This economy size shampoo is economical and can be used for a long period of time.

After hearing his explanation, I consented.

He is struggling to understand mathematics.

He completely understood mathematics.

He was known as a governor in ancient China.

The Tokugawa era is a part of Japanese history.

He found a scoop at the newspaper company.

Jintoku is my best friend.

Tokitaka is my best friend.