Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.

Cell phones are an integrated part of our society at this point, and their main use is communication. They keep students in touch with the rest of the world by giving them the power to interact with it. In my day, if you forgot your lunch you were at the mercy of the office calling home for you. Now, students have the ability to solve their own problems and handle certain "emergencies" on their own.

Cell phones also allow students the ability when the time is right, to keep in touch with students at other schools or friends that don't go to school. While not an educational benefit directly, better relationships can lead to higher self-esteem and reduce isolation, which is good for everybody. In the same way, camera phones allow students to capture the kinds of memories that help build a solid school culture, and, in some cases, can act as documentation of misbehavior in the same way that store cameras provide evidence and deter bad behavior.

Academically, the cell phone can act as to record video of a procedure of explanation that may need to be reviewed later. It could be used to record audio of a lecture, as well, for later review. And just imagine if class could be easily "taped" for students who are absent? What if they could even be streamed and seen from home instantly?

The iPod is a little trickier, because its function varies greatly by model. At its heart, it is a media player, and I know for a fact that many students work better while listening to music. For this reason, they can have a good effect by keeping students from getting too distracted while working (ironic, because we mostly think of them AS distractions!). If it is a WIFI compatible model, and wireless internet is available, the iPod can be a great tool for looking up information or digging into things more deeply. Depending on the model, it may be able to act as a camera and video recorder as well (with the same benefits as the cell phone).

Devices like the Kindle could, conceivably, make learning a lot easier. Imagine carrying all your textbooks in the palm of your hand, rather than strapped to your back! Though expensive, compared to buying new textbooks, the Kindle is a bargain. Many of the books used in high school English classes are actually FREE on the Kindle.

The passage mainly discusses ____.

The word "extensive" in the passage is closest in meaning to ____.