下图为我国华南地区某河谷示意图。读图，完成下列问题。
沸腾是在液体 ____ 和液体内部同时进行的汽化现象．
Look! This is 1 apple tree. I can see many 2. The apples 3red. They are round. How are they? They are 4. Apples, apples, I love 5. An apple a day keeps the doctor away.
