====== GetIndistryD(industry,top) ======
Return a list of colleges which alumnus are most common working in this industry.
====== Description ======
Given a industry, count at which college's alumnus are most common working. The number of industry in mainland China is 7,'金融','房地产','综合','公用事业','商业','工业'.
====== Parameter ======
  - industry: classification industry of listed companies in mainland China
  - top: number of top colleges
====== Return ======
A sorted list of colleges.
====== Detail Information ======
  - given an industry
  - find people who work in this industry
  - map people to college
  - calculate average PageRank of colleges
  - sort and show top colleges