Insight upper, uniT 6: Past modals (certainty - possibility)
It's possible that my brother has bought a new phone. My brother.......................... a new phone. (could/ buy)
could have bought
I'm certain that the girl on the sofa is wearing my jacket. The girl on the sofa............ my jacket. (must)
Must be
It's not possible that my friends have seen this film. My friends............ this film. (can't)
Can't have seen