We have done things we ought not to have done and ________ undone things we ought to have done.
I’m afraid by the time you arrive this afternoon I_______ a lesson then.
In the good care of the nurses, the patient is ____recovering from the heart operation
A modern teaching building has been set up in ______ was a wasteland ten years ago.
The result might not as satisfactory as expected but the ________ on his face told us that he was very happy.
______ to as much English as possible is a good way to learn English well.