Gaokao candidates in Ningbo city, Zhejiang province showing confidence before entering into the exam site, June 7, 2016. [Photo/IC]

Every year's gaokao sees many unusual candidates who are not the typical high school seniors. Some of them are old enough to be the grandparents of the typical candidates. Some have made many attempts to get into their dream colleges. Some just do it for a special reason.

So, who are this year's unusual candidates? Why are they taking the national exam?