• 2022-07-02
    The ratio of the work ______ by the machine to the work _____ on it is called the efficiency of the machine.
    A: to do ...to do
    B: doing....doing
    C: having done ... having done
    D: done ...done
  • D

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    • 0

      Mrs. White made me ______ the work again. A: do B: to do C: doing D: done

    • 1

      With the work _________________, they went out to play. A: doing B: be done C: done D: being done

    • 2

      With the cooking ______,I went on ______ some sewing. A: A.done;to do B: B.being done;doing C: C.to be done;doing D: D.to have done;doing

    • 3

      Lots of homework _____, I must do it now. A: done B: doing C: to do D: is done

    • 4

      You don't know about the difficulty I had ______ the work then at all. A: done B: to do C: for doing D: in doing