to continue working at sth :
Come on, keep at it, you've nearly finished!
KEEP AT STH
Meaning of KEEP AT STH in English
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005
to continue working at sth :
Come on, keep at it, you've nearly finished!
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005