what his parents worried about is he decided not to have breakfast.
Or:
what made his parents worried is .
worry是不及物的,后面得有about.没有的都错.
翻译：令父母担心的是,他决定不吃早餐了.(What)
what his parents worried about is he decided not to have breakfast.
Or:
what made his parents worried is .
worry是不及物的,后面得有about.没有的都错.