There is something happening in the street 和 There is always

There is something happening in the street 和 There is always There is always something ____ in the street There is something in the there is always something happening这是英语书上的一句话,happenning是进行时 在There is always something happening.这句话中happen为什么要加ing 英语翻译There is always something happening(为什么最后的happen要加ing?) There is m____ traffic in the street 【急!】关于There's always something happening 1.there is something in the wind. there is always___ something in the world There is something in the wind there is something in the pond.