Since you ______(visit) this exhibition,over one thousand people ________(be) there.诸位大神若提供了答案还请劳烦提供一下有关知识点

visited have been

1. visited   

   2.have been

Since you visited this exhibition,over one thousand people have been there.
你去了那个展览之后,有超过1000人去了那里
since +时间：自从一个时间点,填动词的过去式
过去某个时间点后,到现在为止又有超过1000人去了,填完成时

Since you __visited____(visit) this exhibition, over one thousand people __have been______(be) there
since”自从......以后“ 后跟过去式，表达的是时间段概念，主句应该用完成时态。