结合所学知识和原理分析材料并回答问题。
运用所学知识分析下列命题：
| 纸币的发行量必须以流通中所需要的金属货币量为基础，否则将导致通货膨胀。 |
参考答案：
解析：纸币是由国家发行并强制流通的货币符号。作为价值符号，纸币的发行量取决于流通中所需要的金属货币量，如果纸币的发行量大大超过流通中所需要的金属货币量，就会导致纸币的贬值和物价的上涨，也就是通货膨胀；相反如果纸币的发行量少于流通中所需要的金属货币量，就会引起物价的下跌和纸币的升值，即通货紧缩。 可见，纸币的发行量如果与流通中所需要的金属货币量不符合时，可能导致通货膨胀，也可能导致通货紧缩。
Do you wake up every day feeling too tired, or even upset? If so, then a new alarm clock could be just for you． The clock, called SteepSmart, measures your sleep cycle, and waits ____（36） you to be in your lightest phase of sleep ____（37） rousing you．Its makers say that should ______（38） you wake up feeling refreshed every morning．As you sleep you pass____（39） a sequence of sleep states---light sleep, deep sleep and REM（rapid eye movement） sleep---that ____（40） approximately every 90 minutes．The point in that cycle at which you wake can ____（41） how you feel later, and may ____（42） have a greater impact than how much or little you have slept．Being roused during a light phase ____（43） you are more likely to wake up energetic． SleepSmart ____（44） the distinct pattern of brain waves _____（45） during each phase of sleep, via a headband equipped _____（46） electrodes and a microprocessor．This measures the electrical activity of the wearer’s brain, in much the ____（47） way as some machines used for medical and research ____（48）, and communicates wirelessly with a clock unit near the bed．You ____（49） the clock with the latest time at _____（50） you want to be wakened, and it _____（51） duly wakes you during the last light sleep phase before that． The _____（52） was invented by a group of students at Brown University in Rhode Island ____（53） a friend complained of waking up tired and performing poorly on a test．“_____（54） sleep-deprived people ourselves, we started thinking of _____（55） to do about it．” Says Eric Shashoua, a recent college graduate and now chief executive officer of Axon Sleep Research Laboratories, a company created by students to develop their idea．
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