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USB series resistors

I have 2 questions:

  1. The USB differential pair D+/D- are impedance-controlled 90 Ohm transmission line.. Why do I need to put a 22 Ohm series termination resistor in it? Isn't that a discontinued resistance in the transmission line that could technically cause reflections?

  2. should I implement TVS diodes on USB and I2C data lines? Thanks