这些植物在潮湿的环境中开始聚集成簇。

The plants started ___clumping together in the damp environment.

他穿着沉重的登山靴在走廊上咚咚地走着。

He was ___clumping down the hallway in his heavy hiking boots.

显微镜下可以观察到血小板的异常聚集现象。

Under the microscope, abnormal ___clumping of platelets was observed.