Smartphones， tablets and other （A） d can be very handy at school. Curious about something the teacher said？ A quick Internet （B） s can turn up more facts. Want to prepare charts and present top-notch class reports？ As the saying goes， there's an App for that.

Mobile devices make it easy to type and organize notes. Calculator Apps can help with math problems. Devices can even （C） r heavy， paper textbooks.

And that's not all. If we have these devices， we can do a lot of things around student interests and projects. For （1） e ， mobile devices often are cheaper and less bulky than regular computers. But， like regular computers， they allow Internet access. With that， （2） s can share ideas and opinions within-or beyond-the classroom. Devices can connect interested students with groups and experts in that field as well.

In general， teachers feel these devices could improve （3） l ， but they also are worried about their students becoming distracted.

Distraction by mobile devices is indeed something to worry about. Jeffrey Kuznekoff studies communications at Miami University Middletown in Ohio. For one recent （D） p ， he let college students take notes during a video lecture. Afterward the students took a test on the material. During the video， one group of students could text or tweet about anything. Another group could text and tweet only if the messages related to the （4） l . A control group couldnt text or tweet at all.

"Texting on things that are unrelated to class can hurt student learning，" Kuznekoff found. Overall， the control and class-related-（E） m groups did 70 percent better on the test than did students that could text and tweet about anything. That control and relevant-message groups also scored 50 （F）

p higher on note-taking. "You're putting yourself at a disadvantage when you are actively engaged with your mobile device in class and not engaged in what's going on，" warns Kuznekoff.

（A， B， C， D， E， F FOR CROSS， 1， 2， 3， 4 FOR DOWN. The first letters of the absents were given.）