If you are sending a text message, watching TV or listening to the radio, you may stop and give this your full attention. Multi-tasking shrinks(使……萎缩) the brain, research suggests.
A study found that men and women who frequently used several types of technology at the same time had less grey matter in a key part of the brain. University of Sussex researchers said, “Using mobile phones, laptops and other media devices simultaneously could be changing the structure of our brains.”
Worryingly, the part of the brain that shrinks is involved in processing emotion. The finding follows research which has linked multi-tasking with a shortened attention span, depression, anxiety and lower grades at school.
The researchers began by asking 75 healthy men and women how often they divided their attention between different types of technology. This could mean sending a text message while listening to music and checking email, or speaking on the phone while watching TV and surfing the internet. The volunteers were then given brain scans which showed they had less grey matter in a region called the anterior cingulated cortex (ACC)(前扣带皮质). Scientists have proved that brain structure can be changed on exposure to fresh environments and experience.
Other studies have shown that training – such as learning to play magic tricks or taxi drivers’ learning the map of London – can increase grey-matter densities(密度) in certain parts.
Experts have also warned of the harmful impact technology can have on our memory and attention span. The University of California team conducted a survey of more than 18,000 people aged between 18 and 99, and found 20% had problems with memory. Researchers were shocked greatly by the 14% of 18 to 39-year-old people who also worried about their memories.
Multi-tasking may shorten attention span, making it harder to focus and form memories, the researchers said, adding that youngsters may be particularly affected by stress.

The underlined word "simultaneously" in Para.2 means _________.

A．on one’s own	B．at no time
C．at the same time	D．by accident

All of the following are possible effects of multi-tasking except _________.

A．saving time	B．a shortened attention span
C．lower grades at school	D．depression and anxiety

What can increase grey-matter densities?

A．Sending a text message while listening to music .

B．Students’ doing their homework.

C．Taxi drivers’ learning the map of London.

D．Speaking on the phone while watching TV.

In which section of a newspaper can the passage be found?

A．Entertainment.	B．Economy.
C．Tourism.	D．Science.

Which of the following can be the best title of this passage?

A．Media multi-tasking is becoming more popular.

B．Multi-tasking shrinks the brain.

C．Multi-tasking may shorten attention span.

D．People are worried about their memories.