I have a headache due to lack of sleep.

I sleep for 8 hours every night.

He looked at the coffin and was devastated by deep sorrow.

The rain was so heavy that it soaked through my umbrella.

He set out on a journey in search of a new world.

My understanding of this issue has deepened.

We need to deepen our understanding of this issue.

During the Great Leap Forward, China's economy changed dramatically.

The Keihanshin region is the center of Japanese culture and history.

He believes that he has supernatural powers.