A、Age. B、Grey matter. C、Language proficiency. D、Brain size. B根据文中“The grey matter in this region increases in bilingual people c

Being bilingual produces changes in the anatomy of the brain, scientists said recently. They said that could explain why children are so much better than adults at mastering a second language.
    They found that people who speak two languages have more grey matter in the language region of the brain. Grey matter in the brain is made up of neurons, or nerve cells. The earlier people learned the language, the larger the grey area.
    "The grey matter in this region increases in bilingual people compared to monolingual people. This is particularly true in people who learned a second language early in life," said Andrea Mechelli, a neuroscientist at University College London.
    Learning another language after 35 years of age also alters the brain but the change is not as great as in early learners.
    "It reinforces the idea that it is better to learn early rather than late because the brain is more capable of adjusting or accommodating new languages by changing structurally," Mechelli said.            "This ability of the brain decreases with time."
    Mechelli’s team used structural brain images to compare the size of the grey matter in the brains of 25 monolingual people, 25 people who learned a second language before the age of five, and 33 late bilingual people.
    However, the scientists do not know whether the change in bilingual people means there is an increase in the size of the cells, the number of cells or the connections between them.