Misc: In which city is Britain's Royal Observatory located?

Questions

at the height of its power, in 400 b.c., this greek city had 25,000 citizens and 500,000 slaves.?

what is the monetary unit in germany?

hyelophobia or hyalophobia is the fear of ____?

in the tv series 'bottom', what was the name of the owner of the pub 'the dirty dick'?

what does a compass's needle point to?