Misc: [Novelty songs name the artist] "Witch doctor"(original)?

Questions

what is thanatology the scientific study of?

on what moor did ian brady and myra hindley dispose of their child victims?

what european country rejected the euro in a referendum in autumn 2000?

what is batman's off-duty name?

who, in 1968, became the oldest singer to get a number 1 hit in britain?