根据对话，选择合适的单词填入下面的横线中。

Sam: What's the ? Why are you laughing?

Lingling: We are going to have a baseball .

Sam: Why are you cups on your head?

Lingling: Amy said, "Bring cups." So I some cups.

Amy: I didn't say "cups". I said "caps".

Sam: It's to make mistakes with English words. I made lots of mistakes with Chinese words.

Amy: Look! What's in my bag?

Lingling: The baseball !

Amy: Then, let's play baseball!