to modify the second commit
third commit
Merge branch 'master' of https://github.com/zhangzhixun/Blackboard

Conflicts:
	README.md
revise
Merge commit 'b36968bd6617f41d81079b9ad8963225119ddee6'

* commit 'b36968bd6617f41d81079b9ad8963225119ddee6':
  the second commit

Conflicts:
	README.md