考查的内容是过去分词作定语、动词不定式作定语的用法：
1、过去分词做定语与其修饰词之间是动宾关系,且过去分词表示的动作已经完成,
first played = which was first played in 776 B.C.
所以应该填first played
2、to be played 是动词不定式作定语,表示将要发生的动作,不符合题意.
《Unit 3 Life in the future》