补全对话 A: Mum, I shall not have lunch at home today. B: 1 ,Linda? A: I want to go to the pet shops at noon with my classmates. Most of the students in our school have their own pets. Mum, as you know, 2 ? B: What kind of pet do you want to have? A: A dog or a cat. I haven't decided yet. B: 3 .It would make much noise. And a dog has to go out every day, and there isn't a dog near our building. And the dog food is expensive. A: 4 .Cats are cheaper than dogs, and 5 ,too. B: Yes, cats are easier to keep.