C
The term “multitasking” originally referred to a computer's ability to carry out several tasks at one time. For
many people, multitasking has become a way of life and even a key to success. In fact, some excellent mental
aerobic exercises ( 大脑训练) involve engaging the brain in two or more challenging activities at a time.
Although checking e-mail while talking on a phone and reading the newspaper may be second nature for some
people, many times multitasking can make us less productive, rather than more. And studies show that too much
multitasking can lead to increased stress, anxiety and memory loss.
In order to multitask, the brain uses an area known as the prefrontal cortex ( 前额叶脑皮层). Brain scans of
volunteers performing multiple tasks together show that as they shift from task to task, this front part of the
brain actually takes a moment of rest between tasks. You may have experienced a prefrontal cortex “moment of
rest” yourself if you've ever dialed (拨电话) a phone number and suddenly forgotten who you called when the
line is answered. What probably occurred is that between the dialing and the answering, your mind shifted to
another thought or task, and then took that “moment” to come back. Research has also shown that for many
volunteers, job efficiency (效率) declines while multitasking, as compared to when they perform only one task
at a time.
Multitasking is easiest when at least one of the tasks is habitual, or requires little thought. Most people don' t
find it difficult to eat and read the newspaper at the same time. However, when two or more attention-requiring
tasks are attempted at one time, people sometimes make mistakes.
We often don't remember things as well when we're trying to manage several details at the same time.
Without mental focus, we may not pay enough attention to new information coming in, so it never makes it into
our memory stores. That is one of the main reasons we forget people's names—even sometimes right after they
have introduced themselves. Multitasking can also affect our relationships. If someone checks their e-mail while
on the phone with a friend, they may come off as absent-minded or disinterested. It can also cause that person to
miss or overlook key information being passed on to them.
49. Why are some mental aerobic exercises designed to engage people in multitasking?
A. To make them more productive.
B. To reduce their stress and anxiety.
C. To develop their communication Skills.
D. To help them perform daily tasks more easily.
50. According to Paragraph 2, why may a person suddenly forget who he has called?
A. He may have his prefrontal cortex temporarily damaged.
B. He is probably interrupted by another task.
C. He is probably not very familiar with the person he has called.
D. He may need a rest between dialing and speaking.
51. People tend to make mistakes when .
A. they perform several challenging tasks at a time
B. new messages are processed one after another
C. their relationships with others are affected
D. the tasks require little thought
52. What is the main idea of the passage?
A. Multitasking has become a way of life.
B. Multitasking often leads to efficiency decline.
C. Multitasking exercises need to be improved.
D. Multitasking enables people to remember things better.[来源:Z#xx#k.Com]
D
My family and I lived across the street from Southway Park since I was four years old. Then just last year
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