Related Clues:
- Soft white limestone
- Calcium carbonate
- Teacher's stick the cause of some white faces?
- Aids after blanking out
- Soft white limestone (as distinct from cheese)
- Baton waves, e.g
- A soft white rock
- Lines of people waiting, we hear, for prompts
- Speaking lines, actors might need them
- Snooker rods
- White rock
- Prompts with the lines audibly
- Prompts rows from what we hear
- Blackboard stuff
- Signals to begin