他对社交媒体有一种不健康的执着，每天要查看几百次通知。

He has an unhealthy ___fixation with social media, checking notifications hundreds of times a day.

他长时间盯着屏幕导致了眼睛疲劳。

His prolonged ___fixation on the screen caused eye strain.

她对完美主义的执着使她无法接受任何微小的错误。

Her ___fixation on perfection made her unable to tolerate even minor mistakes.