(2018 · 山东德州一模 ) Kids who use media in unhealthy ways may have problems 1 . relationships,conduct and other emotional symptoms,lead author of a US new study warned . A study of the University of Michigan(UM) 2 ._________ (release) recently on its website found that how children use the devices,rather than how much time they spend on them, 3 . (be) the strongest predictor of emotional or social problems connected with screen 4 . (addict) . The study revealed that 5 . matters most is whether screen use causes problems in other areas of life or has become 6 . all-consuming activity . Some of the warning 7 . (sign) include:if screen time interferes with daily activities,causes conflict for the child or in the family,or is the only activity 8 . brings the child joy . Though much research 9 . (exist) on adolescents and screen use,this is considered as the first tool to measure how addicted children are to screen media . It will be a 10 . (value) tool for parents,clinicians and researchers .