英语高手帮忙划分一下句子前半部分的成分,Where previous athletes went over the bar while facing it,Fosbury developed a technique where he went over headfirst with his back to the bar.在他以前,运动员过杆时都脸朝下,福贝斯里却设计了一套头先过杆、脸朝上的新技术.

英语高手帮忙划分一下句子前半部分的成分,
Where previous athletes went over the bar while facing it,Fosbury developed a technique where he went over headfirst with his back to the bar.在他以前,运动员过杆时都脸朝下,福贝斯里却设计了一套头先过杆、脸朝上的新技术.