阅读下面短文，根据短文内容回答问题
Is it difficult for you to remember things? I`d like to tell you some ways to improve your memory, so you shouldn`t feel upset.
My first advice is that if you want to remember something well, you have to review it regularly(有规律地). You might review the material two days after you learn it, then a week later, then two weeks later, and then a month later. After a month you will find that you can easily remember the material.
My second advice is to use a colored pen to highlight （标注）the important parts on your book. This will help you in two days. First, it will help you pay attention to the most important parts when you learn the language. It is always easier to remember only the key points. Second, this will make reviewing easier. When you open your book, the colored parts will show you the most important things quickly. In this way, you don`t have to review all the material again.
Another piece of advice is to use the proper time well. First, review all the information in your mind right before you go to sleep. Your brain is working while you are sleeping. If you think about the information before you go to sleep, you might be able to remember it better. Another good time for memorizing information is in the morning because you have just rested and your brain is fresh and clear. So you might also try to review the important information in the morning.
How long may it take you to remember the material easily if you review it regularly?
Is it easier to use a colored pen to help remember the key points?
What is the good time to review information?
How many pieces of advice does the writer give?
What is the passage mainly about?