Hi. You didn't present the columns that your question refers to, which prevents its items from being used in the paragraph. However, the paragraph contains the sentences with perfect and imperfect past tense as the question asked. The past perfect is one that presents a situation that happened in the past and was completely ended. The past imperfect is one that presents a situation that happened in the past and was not finalized. Hope the answer below helps you.
I was taking a shower when my parents' party guests started arriving. I realized I was late and needed to hurry. I dressed quickly and my sister helped me with my hair and makeup. Then I went downstairs and was able to enter the party. My parents were celebrating forty years of marriage and all the guests were having a great time when I arrived. My grandparents were very proud and we took a lot of pictures. The memory of that day still makes me smile, because everyone was so happy and excited.
