夏天的时候，成群的蚊子让我们无法在户外享受夜晚。

In summer, ___swarms of mosquitoes make it impossible to enjoy evenings outdoors.

广场上聚集了一大群抗议者，场面十分混乱。

The square was filled with ___swarms of protesters moving chaotically.

夏天的时候，蜜蜂成群结队地飞向花丛。

In summer, bees ___swarm towards the flowers in large numbers.