| Clue | Source | Date |
|---|---|---|
| Observe silicon and another element at work | ||
| Audit | Thomas Joseph | 04 Mar 2023 |
| Audit | LA Times Daily | 07 Nov 2019 |
| Audit | The Washington Post | 07 Nov 2019 |
| Audit, as a class | New York Times | 26 Jan 2018 |
| Audit, as a class | ||
| Audit, as a class | ||
| Audit, as a class | ||
| Audit | ||
| Attend as a visitor | ||
| Audit, as a class | ||
| Audit | ||
| Audit, as a class | ||
| Audit, as a college course | ||
| Audit | ||
| Audit, as a class | ||
| Take for no credit | ||
| Audit | ||
| Audit a course | ||
| Join, as a meeting | ||
| Attend. |