Modaux de déduction au passé : exercices B1-B2

Complete the following sentences using the appropriate modal verb of deduction in the past form (must have, might have, could have, can't have). Context: Imagine you found an old, mysterious photo in the attic. Choose the correct form for each scenario: 1) The person in the photo is wearing clothes typical of the year $1920$; they ______ (be) my great-grandfather. 2) The photo is blurry, so it ______ (be) taken by a professional photographer; we just aren't sure. 3) My brother claims it is him, but that is impossible because the photo is dated $1920$ and my brother was born in $2005$. Given the time gap, he ______ (be) the boy in the picture.