这句英语句子的结构是怎样的.

题目

这句英语句子的结构是怎样的.
这句英语句子的结构是怎样的?And that was that for another twenty odd years,when by chance i came across an article in a newspaper on research into synesthesia at London hospital

答案

And that（主语） was（系动词） that for another twenty odd years（that引导的表语从句充当表语）,when by chance（时间状语,修饰后面的整个句子） i（主语） came across(谓语) an article（宾语） in a newspaper on research into synesthesia at London hospital（宾补）