1.  The lights are off. They ______ be at home.

2.  She's running — she ______ be late for work.

3.  He ______ be the new manager — I'm not sure.

4.  She knew all the answers — she ______ (study) all night.

5.  He doesn't know about the party — he ______ (hear) about it. (impossível)

6.  The window is open — someone ______ (leave) it open. (possível)

7.  She must forgot the meeting.

8.  He can't to be the driver.

9.  They might be leave already.

1.  can't

2.  must

3.  might

4.  must have studied

5.  can't have heard

6.  might have left

7.  She must have forgotten the meeting.

8.  He can't be the driver.

9.  They might have left already.