长度 + 重量单位换算

{"cm":{"label":"厘米","symbol":"cm","factor":0.01},"in":{"label":"英寸","symbol":"in","factor":0.0254},"m":{"label":"米","symbol":"m","factor":1},"km":{"label":"公里","symbol":"km","factor":1000}}

{"mm":{"label":"毫米","symbol":"mm","factor":0.001},"um":{"label":"微米","symbol":"μm","factor":1.0e-6},"yd":{"label":"码","symbol":"yd","factor":0.9144},"ft":{"label":"英尺","symbol":"ft","factor":0.3048},"nmi":{"label":"海里","symbol":"nmi","factor":1852}}

{"kg":{"label":"公斤","symbol":"kg","factor":1},"g":{"label":"克","symbol":"g","factor":0.001},"lb":{"label":"磅","symbol":"lb","factor":0.45359237},"t":{"label":"吨","symbol":"t","factor":1000}}

{"mg":{"label":"毫克","symbol":"mg","factor":1.0e-6},"oz":{"label":"盎司","symbol":"oz","factor":0.028349523125},"st":{"label":"英石","symbol":"st","factor":6.35029318},"ct":{"label":"克拉","symbol":"ct","factor":0.0002}}