Julie's Homework:

detention
ex) They can't give me (a) detention for this.             NO CORRECTION

long
ex) She has a long brown hair.                                  NO CORRECTION

chew
He is always chewing gum.    He is always chewing a gum.                 

unfair
ex) It's so unfair!                                                  NO CORRECTION

promise
ex) I promise!                                                       NO CORRECTION

trust
ex) Her trust in him was unfounded.            Her trust in him was gone.

EXPLANATIONS:

1. It's more appropriate to use the determiner "a" before the noun "gum." It will make your sentence sound better.

2. The word "unfounded" means without a basis in reason or fact. It's not appropriate for the context that you've created the word "gone" is much better to use to make the message of your sentence to be clearer.

Hi Julie!
Thank you for sending your homework at the Talkfun page. I enjoy checking your homework becasue most of the time your sentences are correct. We will see each other tomorrow and I can't wait to talk to you. Have a great night and see you!
-Teacher Joanna