Next week is Ash Wednesday.

The rise and fall of the Roman Empire is a part of history.

There is still space in this box.

He plays the guitar every day as if he worships music.

The drainage system in this area is very efficient.

His standard of living has improved significantly.

He led the army as a generalissimo.

He is an expert in hydrology and is conducting research on flood prevention.

He is an expert in hydrology, and his research is highly valued around the world.

He was told by the doctor that he might have been infected with hydrophobia.