Bored here!

Another one from the series "Getting to know you":

Do you Americans usually not have a door knocker? Whenever I see someone calling on someone in US TV or movies (e.g. a cop), they're always forced to rap on the front door with their bare knuckles. This must be a pain, literally, if they've a lot of doors to knock, e.g. cops canvasing for witnesses.

Just curious, and it's not my imagination.

While on the subject, what's with those front doors with the three square windows, arranged diagonally across the top of the door? Lack of privacy or what?

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