判断正误I have taken part in many parties since 5 years ago.请讲下理

去掉since 去掉ago 都不对
去掉since
i have taken part in many parties 5 years ago.应该用过去式 而不是完成时 所以同时要把 have taken 改为took
而去掉ago 本身就是错误的 since 5 years ago 是没有错误的 不要改的
其实原句的错误在于 take part in 是非延续性动词 没有完成时
i have been in many parties since 5 years ago.
或者不用完成时 用过去时表达
i took part in many parties 5 years ago.

去掉ago,since引导的时间状语从句,用现在完成时,ago是一般过去时的时间状语,不能混用

错
since 去掉

原句的错误在于 take part in 是非延续性动词 没有完成时
I have been in many parties since 5 years ago.
原句应该为I have been in many parties since 5 years ago