It __can't_ be true. I don’t believe you!
Mike must___ be at the university right now. I saw him 10 minutes ago.
John ___may be a teacher. I don’t really know.
This can't___ be my towel. I can’t recognize it.
She ___must___ be playing the piano now. I can hear music.
This milk ___may go off if you don’t put it into the fridge.
She ___must have been at the meeting when I called her.
They ___may have left for London last week, they didn’t tell me.
She must___ have been running very fast. She was totally out of breath.
Helen has no friends. She ___must be very lonely.
to spread
to know knew known
to choose chose chosen
to rise rose rise