Do Cell Phones Pose Health Problems？

People love cell phones， which is why nine in 10 Americans own one. Many use them hours a day. So even a small cancer risk from their use， if any， could have important （1） h implications. But the question is whether use of cell phones pose a risk of （2） c in the heart or brain？

Most people who are now adults grew up before cell phones were common. But children now use these phones as much as — or more than — （A） a . So children would be experiencing exposure for a much longer portion of their lifetimes. Given that fact， we should look carefully at children's use of these devices. If use of cell phones poses a health （B） p ， the logic is： the more frequently you use them， the higher the risk； the longer you use them， the high the risk.

How can people limit （3） e to cell phone radiation？ Distance is your friend. As with any type of radiation， the dose falls with （4） d . So， don't carry the phone on your body and keep the phone away from your head as much as possible.

Researchers do not yet know how long it might take for a type of tumors to develop in people. It can take a （C） d or longer after exposure to some cancer-causing agents before tumors emerge.

Cell phone use has increased dramatically over the last 30 years， from virtually zero to now most people. And yet， we have not seen any marked （D） i in the rate of （5） b cancers. So it's unwise to conclude that cell phones are （E） d — or are not. But for people who are concerned about the possible danger of cell phones， an easy way is to spend less time on the phone.

（A， B， C， D， E FOR CROSS， 1， 2， 3， 4， 5 FOR DOWN. The first letters of the absents were given.）