闪电

As a result of this episode the caliphs were restricted to a largely symbolic role as merely nominal leaders of Sunni Islam.

由于这次事件caliphs被限制在很大程度上具有象征意义的角色，作为有名无实的领袖的逊尼派伊斯兰教。

Researchers think that in some cases static charges are formed by collisions of rock fragments, ash, and ice particles.

研究人员认为，在某些情况下，静电的电荷碰撞所形成的岩石碎片，灰烬，和冰粒子。