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A $1 \mathrm{~km}$ long microwave link uses two antennas each having $30 \mathrm{~dB}$ gain. If the power transmitted by one antenna is $1 \mathrm{~W}$ at $3 \mathrm{GHz}$, the power received by the other antenna is approximately

1. $98.6 \mu \mathrm{W}$
2. $76.8 \mu \mathrm{W}$
3. $63.4 \mu \mathrm{W}$
4. $55.2 \mu W$