完成下列单位换算:0.28km= {#blank#}1{#/blank#} um= {#blank#}2{#/blank#} nm
83dm= {#blank#}3{#/blank#} um= {#blank#}4{#/blank#} nm
18cm= {#blank#}5{#/blank#} m= {#blank#}6{#/blank#} mm= {#blank#}7{#/blank#} nm
6300km= {#blank#}8{#/blank#} dm= {#blank#}9{#/blank#} mm.