语法填空

　　Ann and Bella are good friends．They are in the same class and sit together．After school, they often go home together．However(尽管如此), they have many different habits．On weekends, Ann likes to stay home, watch TV or sleep, but Bella often 　　1　　(go)out to exercise．Ann eats candy every day, though she knows it's 　　2　　 for her health．Bella likes candy, too, she only eats it 　　3　　(one)a week, because she thinks eating less candy can help her to keep in good health．

　　Today is Ann's birthday．Ann thinks Bella will buy a bag of 　　4　　 for her．But 　　5　　 fact, Bella buys her a book．It's about how to form good habits．

根据句意及首字母补全单词。

I'm a waiter．I'm busy when people go out to d ________．