a cigarette end的用法和样例：
- A cigarette end glowed red in the darkness.
- The cause of the fire was a cigarette end.
- A cigarette end caused the forest fire.
- They were also quite sure that a cigarette end did not start the fire.
- When he dropped a cigarette end in the forest carelessly the dry leaves caught fire.
- It was because somebody carelessly threw a cigarette end that the fire broke out yesterday night.