Hail stones, the size of tennis balls, have been also been reported and officials are warning of rapid moving thunderstorms ahead.”

据悉降落了网球大小的冰雹，官员警告暴雨会快速前移。”

Their goal is to figure out how to decrease the damage hail causes and how Hail stones get so big.

他们的目标是弄清楚如何减少冰雹造成的破坏以及冰雹石如何变得如此之大。