He came down the stairs.

This mutetrahedron plays a very important role in the world of mathematics.

A song praising his courage was playing.

He assisted my project.

He was ignoring my opinion.

He continued to explain earnestly.

Her dress was a beautiful indigo color.

He is deeply interested in pragmatics, especially in Goyouron.

This is a 六角四片四角孔ねじれ正多面體, in other words, a muoctahedron.

This is a model of a muoctahedron.