题目内容：

阅读理解。

Complete the following sentence：“You go to the library to check out ...？” The obvious answer is “books”.But a harder question might be, “What do we mean by ‘books’？” Nowadays, electronic books, or “e­books”， have become more and more popular in American society.

The biggest online bookseller Amazon, for example, recently announced that less than four years after introducing them to its catalog, it is now selling more electronic versions of its book titles than printed ones.

Last week, Pew Internet Project released a survey about the use of e­books by library customers.It found that 12% of Americans aged 16 and older who read e­books say they had borrowed at least one from a library within the past year.But the survey found that the broader public, including 58% of those who have library cards and 53% of people who own electronic book readers, are not aware that they can find and check out e­books from public libraries, even though three quarters of the libraries offer that service.

Pew Internet Project director Lee Rainie noted that e­book borrowing is becoming more popular at the same time that publishers, who are selling plenty of e­books and fewer hard­copy editions, are worried that free e­book check­outs at the library will hurt sales.In February, for example, the big publisher Penguin Books stopped supplying new e­books and audio books to libraries.Penguin just reached an agreement to resume supplying one big library system in New York City but not until six months after new titles are released.That way, those who want the latest books will have to buy them.

So things are a little murky (阴暗的) in the library world when it comes to electronic books.More and more customers want them, but publishers are giving the libraries a hard time about offering them.Demand is not the problem.Supply may soon be.

1.What is the function of the two questions in the first paragraph?

A. To introduce the topic of the passage.

B. To stress the popularity of e­books.

C. To show what the author cares about.

D. To remind us of the change at the library.

2.According to Paragraph 2, what can we know about Amazon?

A. It has sold e­books for five years.

B. Its e­books are cheaper than printed books.

C. It has the best e­books among all libraries.

D. Its e­books sell better than printed books.

3.We know from the survey done by Pew Internet Project that ________.

A. few library customers know how to read e­books

B. the promotional effort at e­book readers is not big enough

C. library customers should be reminded about the e­book service

D. more library cards should be offered to readers free of charge

4.Why did Penguin Books NOT supply new e­books to libraries?

A. Because they are not allowed to offer e­books.

B. Because they wanted to increase the sales of printed books.

C. Because they didn't want their e­books to be copied.

D. Because their products were not welcomed there.