题目

Fifty–eight percent of the teachers interviewed in the Association of Teachers and Lecturers (ATL) questionnaire had come across copying among their pupils. Gill Bullen from Itchen College in Southampton, for example, said, Pieces handed in by two students were identical and significantly better than either of them could have done. Not only that, the essays handed in didn't quite answer the title question I had set. A teacher from Leeds said, I had one piece of work so bravely cut and pasted that it still contained ads from the web page. Connie Robinson from Stockton Riverside College said,抛物线y2=2px(p＞0)的一条过焦点的弦被焦点分成m、n长的两段，则=___________.