The term “multitasking originally referred to a computer's ability to carry out

The term “multitasking” originally referredto a computer's ability to carry out several tasks at one time. For manypeople, multitasking has become a way of life and even a key to success. Infact, some excellent mental aerobic exercises (大脑训练) involve engaging the brain in two or morechallenging activities at a time. Although checking e-mail while talking on aphone and reading the newspaper may be second nature for some people, manytimes multitasking can make us less productive, rather than more. And studiesshow that too much multitasking can lead to increased stress, anxiety and memoryloss.

In order to multitask, the brain uses anarea known as the prefrontal cortex (前额叶脑皮层). Brain scans of volunteers performing multiple tasks together showthat as they shift from task to task, this front part of the brain actuallytakes a moment of rest between tasks. You may have experienced a prefrontalcortex “moment of rest” yourself if you've ever dialed (拨电话) a phone number and suddenlyforgotten who you called when the line is answered. What probably occurred isthat between the dialing and the answering, your mind shifted to anotherthought or task, and then took that “moment” to come back. Research has alsoshown that for many volunteers, job efficiency (效率) declines while multitasking, as compared towhen they perform only one task at a time.

Multitasking is easiest when at least oneof the tasks is habitual, or requires little thought. Most people don' t findit difficult to eat and read the newspaper at the same time. However, when twoor more attention-requiring tasks are attempted at one time, people sometimesmake mistakes.

We often don't remember things as well whenwe'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 makesit into our memory stores. That is one of the main reasons we forget people'snames—even sometimes right after they have introduced themselves. Multitaskingcan also affect our relationships. If someone checks their e-mail while on thephone with a friend, they may come off as absent-minded or disinterested. Itcan also cause that person to miss or overlook key information being passed onto them.

1. Why are some mental aerobic exercisesdesigned to engage people in multitasking?

A. To make them moreproductive.                 

B. To reduce their stress and anxiety.

C. To develop their communicationSkills.         

D. To help them perform daily tasks moreeasily.

2. According to Paragraph 2, why may aperson suddenly forget who he has called?

A. He may have his prefrontal cortextemporarily damaged.    

B. He is probably interrupted by anothertask.

C. He is probably not very familiar withthe person he has called.    

D. He may need a rest between dialing andspeaking.

3. People tend to make mistakeswhen       .

A. they perform several challenging tasksat a time 

B. new messages are processed one afteranother    

C. their relationships with others areaffected       

D. the tasks require little thought

4. What is the main idea of the passage?

A. Multitasking has become a way of life.

B. Multitasking often leads to efficiencydecline.

C. Multitasking exercises need to beimproved.

D. Multitasking enables people to rememberthings better.[来源:Z#xx#k.Com]

试题答案

【答案】

 A

 B

 A

 B

【解析】