Optional B&B:

A. Read the info and the examples

* must have (participle) is used to express a certainty that something happened in the past, normally by deduction. 

For example: "There are shards of glass on the inside, the window must have been broken from the outside!"

* may/might/could have (participle) are used to express deduction about a possibility. For example: "He may have been drinking last night because he looks terrible today!"

* can't/couldn't have (participle) are used to express past impossibility by deducation. For example: "He can't have studied much for the exam because he failed horribly."

* should/shouldn't have are used to express criticism about something in the past, or to express an opinion that something should have been done differently. 

For example: "I shouldn't have had that last beer, I have a terrible headache today!"

B. Write the appropriate modal form in the blank. There may be more than one correct answer. Use a MUST/MAY/COULD/SHOULD + HAVE + PAST PARTICIPLE

1. Someone called me up in the middle of the night. They hung up before I could answer the phone. It (a)  (not be) my brother; he doesn't have a telephone. It (b)  (be) someone I know, but why would they call in the middle of the night? It (c)  (be) a wrong number.

2. Where were you last night? I thought you were going to join us at the movies. You (a)  (have) enough money to go with us, because the tickets weren't that expensive. It's too bad you didn't come. I (b)  (be) able to lend you the money. Or perhaps Peter (c)  (pay) for your ticket. He's so generous. The movie was really funny. You (d)  (be) disappointed to miss all the fun.

3. Sally looked really unhappy as she was leaving school. She (a)  (failed) another exam. I know she's already failed one midtern, and she had two more last week. It (b)  (be) her chemistry test. I know she was really nervous about it. But it (c)  (be) her calculus exam. She's really good at mathematics, and I know she studied a lot for it.