Not until I began to work ______ how much time I had wasted.
We had a party to ________ Mother’s silver wedding.
The book is neither yours nor mine. Whose ________ it be?
On National Day, people sing and dance to ________the birth of our country.
When a pencil is partly in a glass of water, it looks ________ it were broken.
—Is John coming by train?—He should, but he ________ not. He likes drivinghis car.