-Peter: "Would you like a glass of beer?" - David: "Not while I'm _______ ."11/64Mark the letter A, B, C, or D to indicate the correct answer to each of the following sentences. -Peter: "Would you like a glass of beer?" - David: "Not while I'm _______ ."on dutyin the actin orderunder controlGiải thíchĐáp án : A “to be on duty”: đang trong phiên trực/trực nhật