I’m guessing the underlined word was sentimental... in that case full of emotion or feeling would be your answer because that is how she is feeling remembering her friends and experiences... as one does
The correct answer to the given question above is the content of "What Exactly Are Green House Gases". The author in the story "An Inconvenient Truth" uses the content of "What Exactly Are Green House Gases" to emphasize how humans can improve the atmosphere.