Refer to the letter below and answer the following questions.
Dear Valued customer,
Thank you for taking the time to fill out our questionnaire during your stay with us. We do appreciate hearing from our customers, as their comments are vital （53）________ us to continue improving our accommodations.
The problems that you （54）________ have been brought to the attention of our housekeeping department. While the lack of service you experienced is unusual and not the standard of our motel, there is no excuse for a lackadaisical attitude on the part of any of our employees. We are sorry for the inconvenience and annoyance this incident caused.
Thank you again for your comments. We hope that you will give us（55）________ chance to serve you.