Sir, you ______be sitting in this waiting room. It is for women and children only.

Jack described his father，who ________ a brave boy many years ago，as a strong－willed man.

—My goodness! The accident might not have happened if we had done it more carefully.—But we      .

Swimming alone ____ be ____ dangerous. Do be careful.

But for the metal cage to pull the miners to safety, the miners in Chile ____ in less than twenty-four hours.