It should be written in past tense. They're to finish it from a point in it selected by you. They are to put in the main character's thoughts. Remember, the character's thoughts should be consistent with what they know about that character. If they recognize that character is kind and gentle, then that character's thoughts should be kind and gentle.
People think in all tenses.
Those pigs couldn't have made very strong houses. He kept having to spit. But, he did manage to take in a great lung-full of air. When this house goes, my dinner will be running for safety. When he took in a large breath, the house leaned toward him, and when he sneezed, it leaned away.