He was studying ancient documents and found the character '黃門'.

He sneaked into the school through the back gate.

This sluicegate is used to regulate the water level of the river.

His specialty is computer science.

I went to see the Arc de Triomphe in Paris.

He is deeply studying about the classification of superphylum in his biological research.

This book explains in detail how to use the 'Kyūjitai form of 声門' in old Japanese.

There is a large sluice gate in this river.

This organism is classified into the subphylum.

A baby's fontanelle closes a few months after birth.