[单项选择]

Spending 50 minutes with a cell phone close to your ear is enough to change brain cell activity in the part of the brain closest to the antenna (天线). But whether that causes any harm is not clear, scientists at the National Institute of Health said at a conference last month, adding that the study will not likely settle concerns of a link between cell phones and brain cancer. "What we showed is glucose (葡萄糖) metabolism (代谢) (a sign of brain activity) increases in the brain in people who were exposed to a cell phone in the area closest to the antenna," said Dr. Nora Volkow of the NIH, whose study was published in the Journal of the American Medical Association. The study was meant to examine how the brain reacts to electromagnetic fields caused by wireless phone signals.
Volkow said she was surprised that the weak electromagnetic radiation (电磁辐射) from cell phones could affect brain activity, but she said the findings do not shed any light on whether cell p
A. Cell phone use is dangerous.
B. Cell phone use causes cancer.
C. The human brain is an electromagnetic field.
D. There are about 5 billion cell phone users in the world right now.

[单项选择]

Spending 50 minutes with a cell phone close to your ear is enough to change brain cell activity in the part of the brain closest to the antenna (天线). But whether that causes any harm is not clear, scientists at the National Institute of Health said at a conference last month, adding that the study will not likely settle concerns of a link between cell phones and brain cancer. "What we showed is glucose (葡萄糖) metabolism (代谢) (a sign of brain activity) increases in the brain in people who were exposed to a cell phone in the area closest to the antenna," said Dr. Nora Volkow of the NIH, whose study was published in the Journal of the American Medical Association. The study was meant to examine how the brain reacts to electromagnetic fields caused by wireless phone signals.
Volkow said she was surprised that the weak electromagnetic radiation (电磁辐射) from cell phones could affect brain activity, but she said the findings do not shed any light on whether cell p
A. her research has shed light on her understanding of cell phone
B. she found that cell phone exposure is harmful to human brain
C. she found that using a cell phone for about 50 minutes could influence or change brain activity
D. human brain is not responsive to electromagnetic radiation

[单项选择]
Your cell phone holds secrets about you. Besides the names and (51) that you’ve programmed into it, traces of your DNA linger (逗留) on the device, according to a new study.
DNA is genetic material that (52) in every cell. Like your fingerprint, your DNA is unique to you (53) you have an identical twin. Scientists today routinely analyze DNA in blood, saliva (唾液), or hair left (54) at the scene of a crime. The results often help detectives identify (55) and their victims. Your cell phone can reveal more about you (56) you might think.
Meghan J. McFadden, a scientist at McMaster University in Hamilton, Ontario, heard about a crime in which the suspect bled onto a cell phone and later dropped the (57) . This made her wonder whether traces of DNA lingered on cell phones—even when no blood was involved (58) she and colleague Margaret
A. numbers
B. music
C. secrets
D. films