In solfège class, she practiced the si until she could sing the leading tone perfectly.

Si tossed the old coin into the fountain, making a wish for the coming year.

Si announced a new environmental policy at the conference.

Si was a notable prefecture in imperial China, renowned for its administrative and cultural influence in the region.

SI announced a major grant to support research into ocean biodiversity.

During the review, the SI report highlighted severe signal reflections on the high-speed lines.

The doctor diagnosed an SI dysfunction that was causing her lower back pain.

The research team measured the defect density in a-Si thin films after prolonged illumination.

On the shelf, the manuscript was cataloged as Si to indicate its source.

In the old manuscript, several sies appear that seem to function as subject pronouns.