a streak of light的用法和样例：
- A streak of light in the east heralded the dawn.
- There was a streak of light across the sky as a shooting star burned out.
- The man has a streak of cruelty in his character.
- He had a streak of stubbornness.
- He disappeared round the corner like a streak of lightning.
- When she emerged from her cave a streak of light escaped (a streak nowadays people call dawn).