FOCUS 3 second edition 3_2 present and past speculation

The key ___ be somewhere here but I can't find it right now.

• can't

• must

You ___ remember me – we met on a trip to China last year.

• can't

• may

What, you forgot your ticket and passport? You ___ be serious!

• can't

• might

You failed the exam, so your answers ___ have been wrong.

• must

• can't

I'm not sure if you are right. You ___ have made a mistake.

• could

• can't

I might ___ (leave) my mobile at the hotel but I don't remember.

Susan has been travelling for the last two weeks – she must ___ (be) very tired by now.

Wendy's accent is a bit strange. She could ___ (be) Northern Irish, but I'm not sure.

You can't ___ (see) Joe in town at noon – he was at home with me.

Thomas was really upset last week. He must ___ (have) problems at home.