In both pictures there are people standing and talking to each other in front of some kind of building. It may / can/must be a school because on the gates in both pictures I can see a sign with the number of the school on it. In the first picture there are two boys and one girl. They must / can't / should be pupils because they are wearing school uniforms. But they 3 may not / can't/ might not be from the same year - the girl is much younger than the two boys. I'm not sure but the two boys might / can't / must be twins because they look quite similar to each other.
In the other picture, there is a bigger group of pupils and several adults. They're also standing in front of the school. One girl is talking to one of the adults. The woman is certainly not a teacher, she could / can't/ must be the mother or sister of one of the pupils but it's really difficult to say.
In both pictures the people look nervous and they are waiting for something. It may / can't / must be the exam results but I'm not sure. If they are nervous about the exam results, it may not / can't / might not be the school-leaving exam because both pictures were taken in winter and the school-leaving exam takes place in May.
1)can
2)should be
3) can't
4) might
5)could
6)may
7)can't