根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
What is the purpose of readig or studying? If you can't remember what you read or study,it will be a waste of time．   One useful aid that does help you remember what you study is to have a specific purpose or reason for reading．
Why does a clerk in a store go away when your reply to her offer to help is, "No, thank you．I'm just looking．"? Both you and she know that if you aren't sure what you want, you are not likely to find it．But suppose you say instead, "Yes, thank you．I want a pair of sun glasses．" She says, "Right this way, please.”It’s quite the same with your studying. If you choose a book, "just looking" for nothing in particular, you are likely to get just that—nothing． Your reasons will vary; they will include reading or studying "to find out more about", "to understand the reasons for" and "to find out how"．
 Before you start to study, you say to yourself something like this, "I want to know why Stephen Vincent Benet happened to write about America"．Because you know why you are reading or studying, you relate the information to your purpose and remember it better．
Reading is not one single activity.       As you read, you take in ideas rapidly and accurately．But at the same time you express your own ideas to yourself as you react to what you read．You have a kind of mental conversation with the author．
This additional process of thinking about what you read includes evaluating it, relating it to what you already know, and using it for your own purposes     One part of critical reading, as you have discovered, is distinguishing between facts and opinions．Facts can be checked by evidence. Opinions are one's own personal reactions．Another part of critical reading is judging sources．Still another part is drawing accurate inferences．

A．This is an effective studying way.

B．In other words, a good reader is a critical reader．

C．You remember better when you know what you' re reading．

D．At least two important processes go on at the same time.

E．It is important for students to have a positive attitude to their study．
F. But if you do know what you want, you are almost sure to get it.
G．Perhaps you have already discovered some good ways to keep yourself from forgetting．