Let’s do some sleep math．You lost two hours of sleep every night last week because of a big project due on Friday．On Saturday and Sunday，you slept in，getting four extra hours．On Monday morning，you were feeling so bright—eyed that you only had one cup of coffee，instead of your usual two．But don’t be cheated by your energy．You’re still carrying around a heavy load of sleepiness，or what experts call “sleep debt”一in this case something like six hours，almost a full night’s sleep．
Sleep debt is the difference between the amount of sleep you should be getting and the amount you actually get．It’s a shortage that grows every time we skim some extra minutes off our nightly sleep．“People get more sleep debt gradually without being noticed，”says William C．Dement，founder of the Stanford University Sleep Clinic．Studies show that such short term sleep lack leads to a foggy brain，worsened vision，and trouble remembering．Long-term effects include obesity(肥胖)，insulin(胰岛素)resistance，and heart disease．A survey by the National Sleep Foundation reports that we’re losing one hour of sleep each night——more than two full weeks of sleep every year．
The good news is that，like all debt，with some work，sleep debt can be repaid．Adding all extra hour or two of sleep a night is the way to catch up．For the long-term lack of sleep，take it easy for a few months to get back into a natural sleep pattern．
Go to bed when you are tired，and allow your body to wake you in the morning(no alarm clock allowed)．You may find yourself catatonic(有紧张症的)in the beginning of the recovery cycle：expect to have ten hours shut—eye per night；As the days pass，however，the amount of sleeping time will gradually decrease．
So earn back that lost sleep and follow the rules of your innate(固有的)sleep needs. You’ll feel better．“When you put away sleep debt,you become a superman,”says Stanford's Dement，talking about the improved mental and physical capabilities that come with being well rested．
53．If rou have short-term sleep lack，you may         ．   
A．put on weight    B．get heart disease
C．hate eating food D．have a poor sight
54．The example of sleep math is used to show         ．
A．in what case you build up a sleep debt
B．in what way you can make up for lack of sleep
C．why you are energetic even without enough sleep
D．why you need six hours’sleep every night
55．By saying the underlined sentence，Dement means that         ．
A．you need a lot of sleep to be a superman
B．you will be in a good state with enough sleep
C．you need to be a superman to repay sleep debt   
D．you will become a superman with more sleep debt
56．What might be the most suitable title for the passage?   
A．How can you keep energetic?    B．What is sleep debt?
C．Can you catch up on lost sleep?D．Can coffee refresh you?

D
Let’s do some sleep math．You lost two hours of sleep every night last week because of a big project due on Friday．On Saturday and Sunday，you slept in，getting four extra hours．On Monday morning，you were feeling so bright—eyed that you only had one cup of coffee，instead of your usual two．But don’t be cheated by your energy．You’re still carrying around a heavy load of sleepiness，or what experts call “sleep debt”一in this case something like six hours，almost a full night’s sleep．
Sleep debt is the difference between the amount of sleep you should be getting and the amount you actually get．It’s a shortage that grows every time we skim some extra minutes off our nightly sleep．“People get more sleep debt gradually without being noticed，”says William C．Dement，founder of the Stanford University Sleep Clinic．Studies show that such short term sleep lack leads to a foggy brain，worsened vision，and trouble remembering．Long-term effects include obesity(肥胖)，insulin(胰岛素)resistance，and heart disease．A survey by the National Sleep Foundation reports that we’re losing one hour of sleep each night——more than two full weeks of sleep every year．
The good news is that，like all debt，with some work，sleep debt can be repaid．Adding all extra hour or two of sleep a night is the way to catch up．For the long-term lack of sleep， take it easy for a few months to get back into a natural sleep pattern．
Go to bed when you are tired，and allow your body to wake you in the morning(no alarm clock allowed)．You may find yourself catatonic(有紧张症的)in the beginning of the recovery cycle：expect to have ten hours shut—eye per night；As the days pass，however，the amount of sleeping time will gradually decrease．
So earn back that lost sleep and follow the rules of your innate(固有的)sleep needs. You’ll feel better．“When you put away sleep debt,you become a superman,”says Stanford's Dement，talking about the improved mental and physical capabilities that come with being well rested．
53．If you have short-term sleep lack，you may___________．   
A．put on weight    B．get heart disease  C．hate eating food   D．have a poor sight
54．The example of sleep math is used to show______．
A．in what case you build up a sleep debt
B．in what way you can make up for lack of sleep
C．why you are energetic even without enough sleep
D．why you need six hours’sleep every night
55．By saying the underlined sentence，Dement means that______．
A．you need a lot of sleep to be a superman
B．you will be in a good state with enough sleep
C．you need to be a superman to repay sleep debt   
D．you will become a superman with more sleep debt
56．What might be the most suitable title for the passage?   
A．How can you keep energetic?    B．What is sleep debt?
C．Can you catch up on lost sleep?  D．Can coffee refresh you?

You’re standing in the dairy section at the grocery store, searching for your favorite brand. Suddenly, you catch a smell of chocolate cookies. You forget about dairy and head for the bakery (烘烤食品) section. Guess what? You just walked into an odor (气味) trap (陷阱)! The odor was cooked up by scientists in a lab.
For years, scientists have been studying the special powers of smell. They found that more than our other senses, smell changes our mood and helps us remember things.
So companies have begun spending thousands of dollars to scent (使充满香味) entire stores. Artificial (人造的) scents are being used to lead customers by the nose. These smells help to get people inside and put them in the mood to buy. They even make customers remember the store later, so they’ll come back for more. Also, many companies have smartly made use of product smells. A company added lemon fragrance to its dish cleaner. They wanted people to think the soap contained “natural” cleaners. It worked!
New uses for smells are being created every day. One bank, for example, gives customers coupons (优惠券) advertising car loans (贷款). To get people to take out a loan, bank officials hope to coat these coupons with the fresh leather smell of a new car. In Australia, telephone offices are putting sweat odor on unpaid bills. Since some people sweat when they’re scared, this smell might remind them of when they were frightened. And they’ll pay the bills right away!
What lies ahead for our noses? Smell scientists are working on some pretty far-out ideas. Would you believe TV sets that produce smells? Or how about scent diets? Certain food smells will fool your stomach into thinking it’s full. Alarm clocks will scent your bedroom with a strong pleasant smell designed to wake you up. Scientists are even working on ways to keep garbage from smelling. Researchers expect scents to help students make more sense of what they’re learning.
And just think. Someday soon, even your homework may smell nice!
【小题1】How do sales methods affect customers in the stores?