This picture is a computer's wall-paper. It was copied from http://www.3support.com/windows-8-wallpapers/.

    Almost everywhere has doors and windows.  Some of those were very important to us because they brought us the opportunities and challenges.  However, did you think about this question: Which door or window is most important for you?  When I think this question, my answer is COMPUTER with WINDOWS OPERATING SYSTEM.  Maybe you will say that is not a real window, but I must say that computer exactly is a never closed the window of opportunity.

    I use my computer do a lot of things.  I changed my job and found better one through the computer when I worked in China, I searched a lot of useful imformation when I decided came to the United States, and I compared several colleges from Internet when I want transfer to a community college, even I went to City Hall's website made an appointment when I get married with my husband.  No any other doors or windows can bring so many opportunities like computer.  so I think Computer is the most important window for me. And coincidentally, my favorite computer operating system is WINDOWS.