根据对话内容，判断下列句子的正误。
Alex: I like pears. They are sweet. What's your favourite fruit, Lucy?
Lucy: I like apples. They are tasty for me.
Jenny: Is carrot juice your favourite drink, Mike?
Mike: Of course not. Banana juice is my favourite. What about you, Jenny?
Jenny: Ha! Guess. My favourite fruit is round and very big. It's green. It's sweet and juicy. We often eat it in summer. What is it?
Alex: I know! It's the watermelon!
