In hilly country the groundwater table's highest elevation occurs in stream valleys and around lakes. true or false

I would say that this is false and while the groundwater table could be right at the level of stream valleys and lakes, on hills provided they are underlain by permeable sediments or rocks, the groundwater table will be much higher than in the valleys as it usually reflects the topography more or less.

Probably north korea if your family has decided to use only nuclear power.