I can't find my ticket. (must / drop)
You must have dropped it.
One of the students failed the exam.
varied answers
Why is Carl looking so happy? (may, do well on the test)
He may have done well on the test.
You saw an old friend. She had lost a lot of weight.
varied answers
A woman answers the phone. She starts yelling. Why?
varied answers
Ryan handed in his exam. (can't / finish already)
He can't have finished already!
Why is Isabel late for class? (might / oversleep)
She might have overslept.
You had a job interview. They haven't called you.
varied answers
John didn't come to school last week. (Must / sick)
He must have been sick.
Look at her diamond ring!
varied answers
I can't find my notebook! (must, leave at home)
You must have left it at home.