Passage: I want to boil some milk . First , I get out a pan and place it on top of the stove . I remove the milk from the refrigerator . I pour the milk into the pot that is on the stove . I turn the heat up to a medium-high setting . I do n't want to turn the heat up to high because I do n't want it to boil too fast . I watch for small bubbles to appear , which shows the milk is boiling . This takes about 5 minutes for the milk to get hot enough and boil . Once I see many small bubbles in the milk , I turn the stove off . Question: What did they have to wait for once the milk was on the stove? Option1: evaporation to happen Option2: for small bubbles to appear
for small bubbles to appear