He's doing in-depth research on ancient history.
This is my favourite subject.
Mr. Naruhodo's law firm is "The World's Leading Energy Law Firm".
Dr. Kimura gave me your name as the leading scholar in this field.
He is an expert in the area of city planning.
He is working in the field of biology.
He grouped his books into five categories.
He has a great knowledge of the linguistic field.
He is known as a proficient artist in his field.
He is at home in a variety of fields.
He is a trailblazer in this field.
He thought that there was no point in studying further in this field.
Japan is ahead of other advanced countries in electronics.
Japan has caught up with America in some fields.
They have imitated his style in all areas except those that require special skill.
The world has seen a lot of changes in many fields.
Many countries are having difficulties in the economic sphere.
As may be expected of an expert, he's well versed in the field.
Budget items that received priority are education, social security and other fields that are closely related to people's lives.
Desert ecology is a new field of study.