衡量顾客“忠诚”的唯一尺度是（）A.预约 B.重复购买我们的产品与服务 C.满意度高

一个长方体游泳池长15米，宽8米，深2米，要给它的四周和底面贴上瓷砖，贴瓷砖的面积有多大？

证券公司定向发行债券的担保金额原则上不少于债券本息总额的( )。

A．30%

B．50%

C．70%

D．80%

实验室里将一定量的KClO₃和MnO₂混合物加热反应一段时间后，停止加热，冷却至室温，试管中的固体残留物的组成可能有______种情况，请设计一个化学实验，证明其中的一种可能情况，填写表：

阅读理解

     Even facts " forgotten" by people during a busy day may beretrieved if this is  followed  by a good

night's sleep. Researchers from the University of Chicago asked volunteers to remember simple words. 

Many found their memories letting  them down towards the end of the day, but the following morning,

those who had slept well could recall much more. Reserchers , writing in  the journal  Nature .said  the  

brain  coud  " rescue"lost memories during the night.When the brain is first asked to remember something

that memory is laid  down  in  an " unstable " state, meaning that it is possible that it could be lost. At

some point, the brain consolidates  those it deems  important  into a "stable" ,  more permanent state.

     However, the Chicago researchers suggested that it was possible for a " stable" memory to be made "

unstable" agan.This would  mean  that memories could be modified then filed away again in the face of 

new experiences.

The 12 volunteers tested in the experiment were played words created through a speech synthesizer

which were purposely difficult to understand. Initially, the written version of the word was available,but

after wards the volunteers were asked to identify the word from the audio version only. Tests revealed

that the ability to recall the right word tended to tail off as the day ended.    

     However,when the volunteers were retested after a good night's sleep,they were able to recall some

words that they had"forgotten" the previous evening. Dr Daniel, one of the study authors, said : " Sleep 

consolidates memories , protecting them against subsequent interference or decay. Sleep also appears  

to "recover" or restore  memories. " He said : " If performance is reduced by decay , sleep might actively

recover what has been lost. " 

     Dr Karim Nader, from the Department of Psychology in McGill University in Montreal, said: " Memory

research is undergoing a transformation-no longer  is  memory  thought to be a hard-wiring of' the brain ,

instead it seems to be a process of storage and restorage. "    

     Sleep helps some memories " mature" and also prunes out unimportant memories..

1. What does the first paragraph implies?

A. A busy day makes people forget things easily.

B. People need a good night's sleep after a busy day.

C. A good night's sleep helps memories.

D. A good night's sleep helps people forget a busy day.

2. The words the 12 volunteers played in the experiment were not_________.

A. created through a speech synthesizer

B. hard to understand

C. available at the beginning

D. designed to test people's ability of understanding

3. According to the passage , memory _________.

A. is a hard-wiring of the brain

B. is not a process of storage

C. is not a process of restorage

D. will be mature with the help of sleep

4. Which of the following is NOT true?

A. When people first remember something, the memory is in an" unstable  state " .

B. The brain will change those important unstable memories into stable.

C. Once the memory become stable, it will never become unstable again.

D. Sleep can protect memories from being harmed

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