There have three new classmates in their class.(同意句) The teachers know the boy in the art room.

问题描述:

There have three new classmates in their class.(同意句) The teachers know the boy in the art room.
他们身后有一条狗吗?是的。(翻译成英语)

Is there a dog behind them?Yes,there is.
上面到底是同义句还是特殊疑问句还是一般疑问句