He is an expert in theoretical physics.

He is an expert in phytopathology, making a significant contribution to agriculture.

When you cross the International Date Line, the date changes by one day.

Kunminjōon is a book for teaching the correct pronunciation of Hangul.

Infrasound is a type of sound that is inaudible to the human ear.

Debuccalization refers to the phenomenon in phonetics where a specific sound is pronounced outside the oral cavity.

He is an expert in computational linguistics and is involved in the development of artificial intelligence.

Understanding the concept of 'Ha-line conversion sounds' is important in learning Japanese.

Asymmetric Digital Subscriber Line provides high-speed internet connection.

He explained the importance of studying while young, saying 'If you do not study when you are young, it will be difficult to learn when you are old.'