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 organism is classified into the subphylum.

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

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

His incisors are very sharp.

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