Поставьте соответствующую форму глагола to be:
1he.at home last night
2.you ready for the lesson
3i.not late for the lecture
4the students.in the classroom
- you at the concert yesterday
6i.20 last year
7my friend.not there
8we.policeman before school
9i.at a football match last Saturday
10the sky.blue
11nick and pete.friends at school