By the time Jack returned home from England, his son            from college.

 The woman sitting next to me ________ very nervous, for she had never travelled by air.

During the last three decades, the number of people participating in physical fitness programs___ sharply.

—I failed again in the maths exam. How disappointing!—You          it! You never spend time on your maths study.

Keep it in mind not to disturb the president at two o’clock this afternoon, when he ____ a global joint meeting.