why we need MAC address in data link layer?

I need some help with my interview answers for TeleTech. Here are the questions I have to answer and the answers I plan to give to the company. Please could you help I want to make sure I do the best possible. Thank you in advance, Jose 1.New processes and procedures can be disruptive. What actions have you taken when you’ve been asked to significantly change a work process or procedure? What were the results? The only thing I can think of is when the company changed the software they were using to interact with their customers the CRM. It was a little bit challenging. What I did was study the new software in detail to be ready to interact with customer quickly and efficiently using the company's new CRM software. 2.Tell me about a time when you have had to deal with a difficult customer. How did you handle the situation? One time a customer called in to the company and was upset because a technician did not arrive at their house to resolve the problem they were having with their internet not working. So after listening to the customer problem and making sure I understood the problem I showed empathy to the customer and assured the customer I understood the problem and took ownership of the problem making it my own. I reassured the customer I would find a solution to their problem and later found out that the customer was misinformed about the time the technician was suppose to arrive at the customers house, informed the customer of the correct time the technician was scheduled to arrive at her home and apologized for any inconvience that they may have experienced. 3.Sometimes if we’re lucky, we can identify a small error or problem and correct it before it becomes a headache. Has this ever happened to you? Yes, it has one time while I was talking with a customer about a problem they were having logging into the company website. I asked the customer to verify the email address they wanted to use on the company website. After verifying with the customer noticed the customer had the wrong email address on file and immediately changed the customer email address to the email address of the customer. 4. What general questions would you ask a customer prior to starting to troubleshoot their issue? I would first ask the customer what issue they are having? I would then let the customer explain in their own words what they have experienced and not interrupt the customer. After I begin understanding the customer issue I would start using closed ended questions that require more specific answers to narrow down the problem and possible resolution. Next I will verify my understanding of what the customer has told me and get the customer to agree that I understand the issue.(Eg. Okay so your having trouble try to logging into our website it tells you invalid password is that correct?) If the customer agrees then I will proceed to resolve the issue by asking more questions and proceed to the solution. I will not continue until the customer agrees that I understand the issue. 5. What steps should be taken to install software via a CD? First make sure there is no CD in the CD drive if there remove the CD from the computer and put in the CD of the software you are trying to install. Next Open My Computer Within the My Computer window, open the drive that contains the installation files. For example. If they're on a CD or DVD open the D: drive or the letter of the disc drive. Next Within the drive that contains your files, locate either a setup or install file. Double-clicking on this file should start the installation for the program. If you see multiple setup or install files, try to locate the Application file or double-click each of setup or install files until you find the file that starts the installation. Many times the icons associated with the installation files have the same name.