Breakfast Tips

During my childhood, my mother sometimes prepared my breakfast with bread, sweeet milk and cheese. I was wondering why my mother made two holes on top of the sweet milk can (at the opposite direction). Then I asked my mother this question. My mother responded by asking me to try it myself. She gave me a new can of sweet milk, and asked me to make a hole. I did, then what happened? The sweet milk did not flow (pour) out of the can. It is because it needs to have the air flow so that it can push out the sweet milk, as this milk is thick and condensed. So, in conclusion, I learned that to make the two holes is to let the air blow from one side to another, so that it will enable the sweet milk pouring out of the can.