Explanation:

- The sentence is: "The firelight danced on the walls and (3)______ strange shadows around the room."

- Let's check options:

- Option 1: stuck — "stuck strange shadows" doesn't make sense. Shadows can't be stuck around a room.

- Option 2: poked — "poked strange shadows" is also odd. You can't "poke" shadows in this context.

- Option 3: cast — "cast strange shadows" fits perfectly. The firelight can cast (throw or project) shadows on the walls; it's a common phrase.

- Option 4: picked — "picked strange shadows" doesn't fit. Shadows are not picked in this way.

- Correct answer: Option 3: cast

- This keeps the meaning natural and is the most appropriate verb for shadows made by firelight.