Organized by Guangling Secondary School为过去分词短语,它可以做定语修饰限定前面的词。如:
The performance 【organized by Guangling Secondary School】 will start soon.
guangling中学组织的演出很开就要开始了。 此时,括号内的过去分词短语做定语修饰前面的名词performance.
它可以变换为一个定语从句,即:
The performance which is organized by Guangling Secondary School will start soon.
过去分词表被动。
是被动语态,省略了it is