She __________ have left school, for her bike is still here.
—Did you find the missing couple in the mountain yesterday? —No, but we ________ to get in touch with them ever since.
—Such a mistake could have been avoided. —Unfortunately, he ________ the mistake again and again.
The student didn’t pay any attention to the lecture; he ________ of something else.
At the time of the earthquake Jeff was still in his office. He ________ to finish a project before he left for the day.
We ________ to go skiing tomorrow,but there’s no snow,so we’ll just stay home instead。