Since she left, he's buried himself in his work.

自从她走后，他全心扑在工作上。

《牛津词典》

He's been in the doldrums ever since she left him.

自从她离开他以来，他一直很消沉。

《牛津词典》

She has studied English in the school since she left her hometown.

自从她离开家乡以来，她一直在学校学英语。

youdao

said the man gently. "I've been with you today, and every day,almost, since--since she left us.

VOA: special.2010.05.15

Miss O'Callaghan, 22, had not been seen since she left a nightclub in Swindon early on Saturday morning.

BBC: Sian O'Callaghan

Those are the words of Jesica McBride, from Coventry, who has been out of work since she left school last year.

BBC: Boot camp

Moira's tortured family have not known what happened to her since she left her family home in Coatbridge on 23 February 1957.

BBC: Glasgow & West Scotland