In this chemical reaction, hydration plays an important role.

This area is rich in subterranean rivers, which serve as a source of groundwater.

He was my student, but now he has become so proficient that it can be said 'the student has surpassed his teacher.'

In linear algebra, the upper triangular matrix plays a very important role.

The grammar of 'Jou-nidan' is an important part in learning Japanese.

My room is on the upper level.

This handover is our new project.

His efforts finally brought about a spectacular result.

He is doing special exercises to strengthen his supraspinatus muscle.

By training the superior oblique muscle, there is a possibility that your eyesight can be improved.