9.visual_mode

" three sub mode  
    v                 active char visual  
    V/shift+v    active line visual  
    Ctrl+v         active chunk visual  
  
" visual operator  
    gv          reselect last hlselect  
    o           swich selection boundary  
  
------------------  
vi{             select content in {  
.               repeate last oprator  
vit             select content in tag   
U/u             Upper/lower  
r               replace selection. then tap ESC effect on multi line  
c               delete and insert. then tap ESC effect on multi line  
Ctrl+v          rect selection. then tap $ include extent chars. then tap A append end. then tap ESC effect on multi line