I had a similar problem, but it was due to assuming that the sensor tag would default to false, but it is in fact required.
Google Distance Matrix API has a limit of elements set to 2500. I highly doubt it that you would have gone over this limit, as you would have to have calculated the maximum 10 x 10 matrix 25 times over. I am from South Africa, and it refused to work for any local addresses until I changed the transport mode to driving (from walking, I mean seriously, we have cars).
Maybe that'll help.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.