Adjective or adverb? Fill in the blanks below with the correct form.

Holly is an (intelligent) girl. She works (diligent) on her homework and (constant)  gets (exceptional) grades. She is   (amazing, bright), her teachers all agree. Holly is (grateful) that her school performance is above average. She has an (unusual) talent for math, but she is (extreme, careful) not to brag about her (easy) grasp of numbers. Others in her class look at her (envious) and speak (sarcastic) about her even though she is (generous) with her time and helps her classmates. This often makes her (unhappy) and she has more than once cried (unhappy) into her pillow. “People can be so ” (cruel), she complained (bitter) to her best friend. “You are my only friend,” she said (grateful) to the girl sitting (quiet) beside her. Her friend hugged her (warm) and said in a (choking) voice. “I’ll always be your (faithful) friend and stand by you (faithful).”