He achieved a tan'yao in mahjong.

Please disconnect the power.

He is an expert in physics.

He loves physics and studies it in the library almost every day.

I am majoring in physical chemistry at university.

He is a world-renowned bacteriologist.

He is a world-renowned biologist.

He is traveling around the world as an ecologist.

He is a world-famous archaeologist.

He is a beginner in Japanese.