阅读下面短文，从每所给的A、B、C、D四个项中选出最佳选项。
Do you use a calendar to help you organize your life? By listing what you need to do on any special day, you can make sure to keep all for your appointments and not worry whether you've forgotten something. Calendars are also useful for reminding(提醒) people what day a certain holiday is on and what days you might have off from work. Besides, they are used for planning fun things like vacations and outings.
A calendar is usually divided into twelve parts, and each one stands for m month with all the days laid out in a grid-like (网格状的) form. A block of space usually is for are day, and there is enough space for you to write down what you need to do on that certain day. You probably use all different kinds of calendars. A calendar on your cell phone screen is easy to use, and so is a large paper calendar that hangs on your wall.
Here is one page of Mary's calendar and it shows her plans in May.
