Searching the Internet may help middle-aged and older adults keep their memories sharp,US researchers said. Researchers at the University of California, Los Angeles ,studied people doing web searches by recording their brain activity. "What we saw was people who had Internet experience used more of their brain during the search,"Dr.Gary Small, a UCLA expert on aging, said,"This suggests that just searching on the Internet may train the brain and that it may keep it active and healthy." "This is the first time anyone has simulated an Internet search task while scanning the brain,"Small said. His team studied 24 normal volunteers between the ages of 55 and 76. Half were experienced at searching the Internet and the other half had no web experience. However, the two groups were similar in age, gender and education. Both groups were asked to do Internet searches and book reading tasks while their brain activity was monitored. "We found that in the book reading task, the visual cortex-- the part of the brain that controls reading and language -- was activated,"Small said,"In doing the Internet search task, there was much greater activity, but only in the Internet-savvy group." He said it appears that people who are familiar with the Internet can engage in much deeper level of brain activity. Activities that keep the brain engaged can preserve brain health and thinking ability. Small thinks learning to do Internet searches may be one of those activities. According to the passage, we can learn that  _  .
reading books keeps the brain more engaged searching the web keeps the brain more engaged watching TV keeps the brain more engaged chatting online keeps the brain more engaged