Can't is often used when we think that something is impossible at the present moment.
"Helen can't be in Spain because I saw her driving past my house this morning."
Can't have + past participle is used when we are sure that something did not happen in the past.
"He can't have been at the meeting, he's on a business trip this week."
"They can't have bought it today because the shops are closed."
Now choose the correct form to complete each sentence.