Tom was disappointed because most of the guests________when he________at the party．

I watched the girl step off the sidewalk, ____the road, and ___ into the post office.[ ]

_______ the help of my teacher, I worked out the problem in the end.

Did they have a good time at the party?—Judging by their smiles, they _________ have enjoyed themselves.

“Well done, John! Not a single mistake____in your exam paper this time!”said the teacher．