.--- I didn't attend the meeting yesterday. --- But you _______. A ought to B should to C ought have D should have
Most air pollution is caused by the burning of _________ like coal, gas and oil.
I bought a dress for only 10 dollars in a sale; it was a real _________.
—Shall we go out for a walk? —Sorry. This is not the right _________ to invite me. I am too tired to walk.
The top leaders of the two countries are holding talks in a friendly _________.
The young man made a _________ to his parents that he would try to earn his own living after graduation.