将下列句子重新排序,使其成为一段通顺的对话
a. At half past seven.
b. Good morning, Bob. What time did you have breakfast today?
c. I had a hamburger and some cola. I often have these for breakfast.
d. What did you have for breakfast?
e. Good morning, Joe.
f. That's not healthy. You should eat vegetables and drink some milk.