选择合适的单词填空。

bell    ago    help    gatekeeper    neck

John：You look unhappy．What's the matter, Joe? Can Iyou?

Joe：I lost my cat．

John：What does your cat look like?

Joe：It's black．There's aaround her．Did you see it?

John：I saw it twenty minutes．It was near the gate．

Joe：Let's go and ask the．

John：OK．Let's go．