Hello David,

Thank you for submitting your homework, Here some corrections for your composition please study about it.. Thank you..^_^

We have 3 school president at my class exempt me.
Correct: We have 3 school president in our class except me.
**Use the preposition "in" to mean inside a place or group.
** Use the word "our" to mean you and others.
** The word "except" is more appropriate for this sentence

Our school we select 2 girls and 2 boys in 1 class.
Correct: In our school we select 2 girls and 2 boys in 1 class.
** Use the preposition "in" to mean inside a place or group.

Their are smart and kind.
Correct: They are smart and kind.
**Instead of using "their" use "they" to mean a group of people.