题目内容：

Teachers say the digital age has had a good influence - and a not-so-good influence - on this generation of American teenagers．More than 2,000 teachers took an online survey．Three-quarters of the teachers said the Internet and digital search tools have had a "mostly positive" effect on their students' research habits and skills．But 64 percent said the technologies "do more to distract（使 - - - ---分心） students than to help them academically．" And 87 percent agreed that these technologies are creating an "easily distracted generation with short attention spans．"

The Pew Internet Project did the survey with the National Writing Project．Judy Buchanan is the vice director of the National Writing Project and a co-author of the report．Ms．Buchanan says digital research tools are helping students learn more and faster．"Teachers really favor these tools because they are ways to make some of the learning exciting and engaging．Young people favor these tools．The goal is to really help them become creators of meaningful content, and not just sort of consumers．"

But one problem the survey found is that many students lack digital literacy．They trust too muck of the information they find on the Internet．Judy says these students haven't developed the skills to determine the quality of online information．"It's something that really has to be taught and paid attention to．Because in a world in which things happen quickly, you do need to step back, reflect and analyze the information you have．"

Another problem is blamed on something that might not seem like a problem at all: being able to quickly find information online．Teachers say the result is a reduction in the desire and ability of their students to work hard to find answers．They say students are overly dependent on search engines and do not make enough use of printed books or research libraries．

Many teachers are also concerned that the Internet makes it easy for students to copy work done by others instead of using their own abilities．

1.The text mainly tells us____．

A．all the students use digital tools

B．the Internet is playing a key role

C．teachers encourage using digital tools

D．digital tools bring about benefits and problems

2.Which of the following best shows the structure of the text?

3.The underlined sentence in the third paragraph probably means

A．students do not have the right digital tools

B．students do not always have access to the Internet

C．students haven't the ability to adjust themselves

D．students can't judge online information properly

4.Some students don't tend to work hard because

A．they can get answers on the Internet quickly

B．printed books and libraries around aren't enough

C．the Internet can't make students concentrate

D．they can copy each others' work without being punished