研究：约半数美国青少年一直在线 Nearly half of American teenagers – children ages 13 to 17 - say they are online “constantly” despite concerns about the effects of social media and smartphones on their mental health.

研究：大多数美国青少年不喝酒不吸烟 Drug use among teenagers has continued to drop since the early years of the COVID-19 pandemic, a large national study says.