Aboutfiveyearsago,whenthefirstgenerationofwearablefi...
问题详情： Aboutfiveyearsago,whenthefirstgenerationofwearablefitnesstrackersbecamepopular,theywereannouncedasthedawnofarevolution.Healthexpertsandbusniesspeoplealikesaidthatgivingpeopleaccesstoreal...