1
1.a
2.-
3.A
4.-
5.-
2
1.a box-boxes
2.a man-men
3.a child-children
4.a woman-women
5.an elephant-elephants
6.a mouse-mice
7.a tooth-teeth
8.a foot-feet
9.a dog-dogs
10.a fish-fish
3
1.There were five lessons yesterday
2.There is a big birthday cake on the table
3.There are pupils in the classroom
4.There was a nice Chrismas tree at school last year
5.There is no teacher in the classroom