We_______on this project for four hours. Let’s have a rest.

A. are working     B. have been working    C. worked      D. had worked

——Is there any possible way to help them get rid of such a bad habit?

   ——To tell the truth, it’s very hard. But we_______ on this problem.

A. worked                      B. had worked                C. are working                 D. had been working

We_______on this project for four hours. Let’s have a rest.

A. are working     B. have been working    C. worked      D. had worked

We _______ on this project for four hours. Let’s have a rest.

    A. are working      B. have been working

    C. worked          D. had worked

—Is there any possible way to help them get rid of such a bad habit?
—To tell the truth, it’s very hard. But we ________ on this problem, trying to improve the situation .