Water shortage in this area will be a serious problem to the people,_much has been done.

问题描述:

Water shortage in this area will be a serious problem to the people,_much has been done.

though/although/as,两个句子表转折。句意“虽然该地区水资源短缺已经有所改善,但是对于该地区的人们来说,这仍将是个严重的问题”

意思:
这个地区的缺水将是一个严重的问题,一些人已经做了

though
意思是:尽管已经做了很多工作,这个地方的缺水问题对当地人民来说,仍然会是个非常严重的问题.