train from young ma....
while us human beings, we know what are not to eat - dirty food
etc.
Sometimes if we are 'too clean', then when kena a bit of dirty
food we will get sick easily liao.
Like i go back indo then eat the food there, come back LS liao.
Cuz we are too used to clean food. Then when suddenly kena a bit of
bacteria then cannot tahan liaos lors.
And also, how you know the cats and dogs nv fall sick?
They run towards you and tell you? 
