Have you ever forgotten to zip your schoolbag? Many times when i was walking on the campus, i saw some students walking with an open schoolbag,which looks like a huge mouth...well that's really awkward, lol Sometimes I go forward and tell him/her :"hey, you forget to seal your bag~", though it's none of my business... Actually such mistake never happened to me, am I too cautious? heheh I'm wondering why they made such mistakes?... Yeah, it's a wierd question...lol