题目内容：

    Students at Empire High School started class with no text books-but it wasn't because of money problems.

Instead, the school gave iBbooks-laptop computers to each of its 340 students, becoming one of the first US public schools to stop printed textbooks.

School officials believe that the electronic materials will make students enjoy learning more Empire High School was designed to have a textbook-free environment.

Students at Empire High School get the materials over the school's Internet network. The school has a central control system that limits what can be downloaded at the school.

“Students can hand in homework online. We have a web program that helps to check if you copy from others,” the headmaster Baker said.

In addition to offering up-to-date information, teachers can make the lessons more enjoyable. For example, lessons in history can include links to a person's daily life, his ideas, his discovery, and so on.

Social studies teacher Jeremy Gypton said the change was easier than expected. Gypton said he assigned reading based on websites, used online groups and message boards to keep the students connected. And he also asked them to comment on each other's work.

Julian Tarazon, a new student, said that it was kind of hard at first, because you had to put things in folders(文件夹). But after a couple of days, you got used to it. Another student Morgan Northcutt said the computer system had made it easier to do homework.

The school isn't completely paperless, however. It has a library, and students can read books in it.

“We're not trying to get rid of book,” Baker said. “We love books.”

1.What can a central control system help to control?

A.What to download. B.Why to download.

C.How to download. D.How much to download.

2.What is the biggest advantage of the homework online?

A.Students can do it anytime.

B.Information online is available.

C.There is a lot of reading based on websites.

D.It provides a platform for students to share ideas.

3.Why did the teachers at Empire High School begin to use iBooks?

A.They had money problems. B.They had limited network.

C.They wanted a web program. D.They wanted to improve their teaching.