cluster of particle

例句：

1. 1.The birds are clustered in the treetops.
   鸟儿们聚集在树梢上。
2. 2. The flowers are clustered around thebase of the tree.
   花朵围绕着树的底部聚集。
3. 3. The scientists gathered at the conferenceto discuss their findings.
   科学家们聚集在会议上讨论他们的发现。