首先应该做这个。

　　This is the first thing to do.

　　You should do this first.

　　你掉了这个。

　　You dropped this. *drop “掉下，丢下”。

　　You dropped this. (你掉了这个。)

　　Oh, yeah. It's mine. (哦，对!是我的。)

　　我想这是你丢的吧!

　　I think you dropped this.

　　I think this is yours. (我想这是你的吧。)

　　这是你的吗?

　　Is this yours?

　　Did you drop this?

　　这不是你的吗?

　　Isn't this yours?

　　Doesn't this belong to you?

　　是我的。

　　It's mine.

　　Yes, that's mine. (是的，那是我的。)

　　Yes, it's my handkerchief. (是的，是我的手绢。)

　　It belongs to me.

　　我的钱包丢了。

　　I've lost my wallet.

　　这下可麻烦了。

　　I'm in trouble! *be in trouble 表示“陷入困境”。