There (has,have )to be some people left in that town after yesterday's flood.

问题描述:

There (has,have )to be some people left in that town after yesterday's flood.

这个句型是由have to do(不得不,一定)和there be (存在有)结合在一起的,可以理解成一定要(有)
昨天的洪水过后一定要留几个人在那个村子里.

have
主语是some people