Ответ:

1 Write sentences using have / has and the past participle of the main verb.

I / must / turn off / the computer last night

I must have turned off the computer last night.

1 He hasn't gone to the hospital yet. They can't have operated on him.

2 Helen is crying. She could have had an argument with Ted.

3 Mum isn't here. She might have gone shopping.

4 He looks happy. He must have passed the test.

5 She was on her own. She can't have got together with her friends.

Думаю что так!