a swarm of flies的用法和样例：
- He spoke, and there came a swarm of flies And gnats in all their territory.
- "Not even a swarm of flies disturbs a cheetah's after-dinner catnap.
- A swarm of mosquitoes fly into the room.
- A swarm of journalists followed the film star's car.
- She left amid a swarm of photographers.
- He has received a swarm of letters.