good idea, but text books are updated to new version after one o

sometimes, the page doesnot match anymore.
not sure how she solve that problem.  it still has risk there.

所有跟帖： 

• yes, professor often change their books, that sucks -LordofMoney- ♂ (0 bytes) () 09/24/2013 postreply 07:06:03

• Normally, it will take about 2 to 3 years to change edition -planotx- ♂ (156 bytes) () 09/24/2013 postreply 07:51:10

• 这主意我也想过 -aywl- ♀ (69 bytes) () 09/24/2013 postreply 17:09:08