①∵1nm=10-9m,∴7.261×103nm=7.261×103×10-9m=7.261×10-6m;
∵1nm=10-12km,∴7.261×103nm=7.261×103×10-12km=7.261×10-9km;
②∵1h=3600s,1min=60s,∴3h11min=3×3600s+11×60s=11460s;
③∵1km/h=
m/s,∴108km/h=108×1 3.6
m/s=30m/s;1 3.6
④100cm/min=100×
=100×10-5×60km/h=0.06km/h.10?5km
h1 60
故答案为:7.261×10-6;7.261×10-9;11460;30;0.06.