—Why are your eyes so red？You________have slept well last night.—Yeah，I stayed up late writing a report.                          (

Being constantly exposed to advertisements is annoying, but it ______ be pleasant sometimes.

The winner of the race is tall and thin; he _______ be my friend, Mike, who is short and fat.

---Must I go to medical school and be doctor like you，Dad？--- No, you __________, son. You’re free to make your own decision. 

It was playing video games that took the boy too much time that he          have spent learning．