Помогите кто может, пожалуйста. Буду вам очень благодарна. Номер 82 и 83.

82
1
a) I am at school.
b) I was at school.
2.
a) He is in bed.
b) He was in bed.
3.
a) They are in Africa.
b) They were in Africa.
4.
a) It is in the box.
b) It was in the box.
5.
a) We are at the zoo.
b) We were at the zoo.

83
1. Is he at school? - Yes, he is.
2. Was he at school? - Yes, he was.
3. Can he swim? - Yes, he can.
4. Could he swim? - Yes, he could.
5. Were they in Russia? - Yes, they were.