Choose the correct modal constructions.

Choose the correct option.

"Why didn't the factory work yesterday?" — "The workers [might have been|might be|should have been] on strike."

We [can't have seen|must see|must have seen] Frederic; he was sitting next to us.

Call the lost and found office and ask them about your handbag. Someone [needn't have found|should have found|could have found] it.

Alex [can't have travelled|might travel|should have travelled] abroad on his last vacation. His international passport has recently expired.

The teacher explained the task, but Helen completed it incorrectly. She [mustn't have misunderstood|should have misunderstood|must have misunderstood] the explanation.

You [should have cooked|needn't have cooked|must have cooked] so much food; we're on a diet.