Practice 2　　● You are in charge of security department in your company. You have just received a letter from the Customer Services Manager at Guardian Co., who are installing a new monitoring system at your offices.
　　● Look at part of the letter below, on which you have already made some handwritten notes.
　　● Then, using all your handwritten notes, write a letter to Guardian’s Customer Services Manager.
　　● You do not need to provide postal addresses.
　　● Write 120-140 words.