My father sometimes has to be ___________ a night shift at the factory.Đoạn văn21/55II. LANGUAGE FOCUSa. Choose the one word or phrase - a, b, c or d - that best completes the sentences or substitutes for the underlined part.My father sometimes has to be ___________ a night shift at the factory.in at onoverGiải thíchĐáp án đúng là c.