Complex sentence: The two additional differential pairs are for SuperSpeed data transfer, that support dual simplex SuperSpeed signaling; while the GND_DRAIN pin is for drain wire termination, and to control EMI and maintain signal integrity.
Split into simpler sentences: The two additional differential pairs are for SuperSpeed data transfer; they are used for dual simplex SuperSpeed signaling. The GND_DRAIN pin is for drain wire termination and to control EMI and maintain signal integrity.