git is a distribuated version control system;
git is free software distribuated under the GPL;
git has mutable index called index;
git tracks changes of files;
my stupid boss still prefers SVN.
abandon the ~ file 
the third modification
the fourth modify
the fifth mod
i creat a new branch.
creating a new branch is fast and simple.
creat branch 3 and add some content.
take advantage of another merge .