[填空题]
If the velocity of blooob gw 8.t4o,rbj-hygjq*/g fa; kzc66d flow in the aorta is normally ab82) eeteygs/dlnz:2 -ro0mpn out 0.32 m/s what beat feez:-2) td2rsenn/ gmy8lop0requency would you expect if 5.50-MHz ultrasound waves were directed along the flow and reflected from the red blood cells? Assume that the waves travel with a speed of $1.54 \times10^{3 }$ m/s $ \times10^{3 }$Hz
