Happy birthday! Do birthday really make people happy? Of course they do．Birthday celebrate the day when we were born．Besides, that extra candle on the cake suggest another year of growth and maturity（成熟）—or so we hope．We all like to imagine that we are getting wiser and not just older．Most of us enjoy seeing the wonder of growth in others, as well．For instance, seeing our children develop and learn new things makes us feel proud．For Americans, like people in most cultures, growing up is a wonderful process．But growing old? That is a different story．

Growing old is not exactly for people in youth-oriented（以年轻人为中心）American culture．Most Americans like to look young, act young and feel young．As the old saying goes, “You’re young as you feel．” Older people joke about how many years young they are, rather than how many years old．People in some countries value the aged as a source of experience and wisdom．But Americans seem to favor those that are young, or at least “young at heart”．

Many older Americans find the “golden years” to be anything but golden．Economically, “senior citizens” often struggle just to get by．Retirement at the age of 65 brings a sharp decrease in personal income．Social security benefits usually cannot make up the difference．Older people may suffer from poor nutrition, medical care, and housing．Some even experience age discrimination（歧视）．American sociologist Pat Moore once dressed up like an older person and wandered city streets．She was often treated rudely--even cheated and robbed．However, dressed as a young person, she received much more respect．

Unfortunately, the elderly population in America is increasing fast．Why? People are living longer．Fewer babies are being born．And middle-aged “baby boomers” are rapidly entering the group of the elderly．America may soon be a place where wrinkles（皱纹）are “in”．Marketing experts are ready noticing this growing group of consumer．

Title: Different Opinions About 1._____________Old.

The biggest safety threat（威胁）facing airlines today may not be a man with a gun ,but the man with portable（便携式）computer in business class .In the past 15 years ,pilots have reported about over 100 incidents that could have been caused by electro-magnetic interference(电磁干扰) .The source of this interference remain unclear ,but increasingly ,experts are pointing the blame at portable electronic devices（设备）such as portable computers ,radio and mobile telephones .
RTCA ,an organization which advises the aviation industry ,has suggested that all airlines ban, such devices from being used during “key” stages of flight ,particularly take-off and landing .Some experts have gone further ,calling for a total ban during all flights .Nowadays ,rules on using these devices are left up to airlines. And although some airlines ban passengers from using such equipment during take-off and landing ,most are not willing to exercise a total ban ,if many passengers want to work during flights .
The difficulty is understanding how electromagnetic fields might affect an aircraft’s computers .Experts know that portable devices give off radiation which affects those wave lengths which aircraft uses for communication .But because they have not been able to reproduce these effects in a laboratory ,they have no way of knowing whether the interference might be dangerous or not .
The fact that aircraft may be in trouble because of the interference raises the danger
that some people may use radio systems in order to damage navigation（导航）equipment .As worrying ,though ,is the passenger who can’t hear the instruction to turn off his radio because the music is too loud .
【小题1】.
.What is said about over 100 aircraft incidents in the past 15 years ?
A They may have taken place during take-off and landing .
B They have been caused by the damage to the radio systems .
C They were said to have resulted from electro-magnetic interference .
D They were caused by the passengers’ portable computers .
【小题2】.
. Few airlines want to refuse a total ban on their passengers because ____ .
A they have other effective safety measures to fall back on
B they don’t believe there is such a danger as radio interference
C the effect of electromagnetic interference is yet to be proved
D most passengers refuse to take a plane which bans the use of radio 
【小题3】.
. Why is it difficult to see the effects of electromagnetic fields on computers ?
A Experts lack proper equipment to such research .
B It is dangerous to carry out such research on an airplane .
C It remains a question what wave lengths are to be interfered with .
D Scientists are not able to produce the same effects in laboratory .
【小题4】.
It can be inferred from the passage that the author ___ .
A hasn’t formed his own opinion on this problem
B has fully understood the danger of electromagnetic interference
C regards it is as unreasonable to exercise a total ban during flight
D is in favor of banning passengers’ use of electronic devices

New evidence shows that getting enough Vitamin D may be the most important thing you can do for your health．

You know the usual prescription for good health: a balanced diet with lots of fruits and vegetables, regular exercise, no smoking．Now add this: Spend a little more time in the sun．

    Huh? That may sound like medical heresy （反面观点）．After all, we've been warned for decades about the dangers of the sun: wrinkles, age spots and the increasing threat of skin cancer．But new and impressive medical evidence suggests that sunlight is beneficial．The vitamin D it prompts our bodies to make may prevent cancer, protect against heart disease and ward off a long list of disorders such as multiple sclerosis, rheumatoid arthritis, diabetes and gum disease．It is even showing promise as a treatment for heart disease and some cancers．

    Long recognized as vitally important for bone building （it's needed for calcium absorption）, vitamin D has now achieved superstar status among nutrients．While all doctors may not agree, many experts are confident enough of its wide-ranging powers to urge that we get much more of it, from the sun and from supplements, as even the best diet in the world may not give us enough．

Which of the following is NOT the usual way of keeping healthy?

     A．To do exercise now and then．

     B．To eat plenty of fruits and vegetables．

     C．To avoid staying in the sun for a long time．

     D．To keep away from cigarettes．

What does the underlined word “prompts” in the third paragraph mean?

     A．causes              B．forces          C．motivates    D．encourages

According to the passage, vitamin D ________．

     A．can be got by doing regular exercise

     B．can be used to prevent some cancers

     C．can be got from the sunlight

     D．can be used to remove the wrinkles

The passage is most likely from a（an） ________．

     A．advertisement       B．news report        

       C．magazine             D．medical prescription

 Moods, say the experts, are feelings that tend to become fixed, influencing one’s outlook for hours, days or even weeks. That’s great if your mood is a pleasant one, but a problem if you are sad, anxious, angry or simply lonely.

  Perhaps the best way to deal with such moods is to talk them out; sometimes, though, there is no one to listen. Modern pharmacology（药理学）offers a lot of tranquilizers（镇静剂）What many people don’t realize, however, is that scientists have discovered the effectiveness of several non-drug methods to set you loose from an unwanted mood. These can be just as useful as drugs, and have the added benefit of being nonpoisonous. So next time you feel out of sorts, don’t head for the drug-store but try the following methods.

  Of all the mood-altering self-help techniques, aerobic exercise seems to be the most efficient cure for a bad mood. “If you could keep up the exercise, you’d be in high spirits, ” says Kathryn Lance, author of Running for Health and Beauty.

  Researchers have explained biochemical and various other changes that make exercise compare favourably to drugs as a mood raiser. Physical exertion such as housework, however, does little. The key is aerobic exercise—running, cycling, walking, swimming or other repetitive and sustained activities that increase the heart rate, increase blood circulation and improve the body’s use of oxygen. Do some of the activities for at least 20 minutes a session three to five times a week.

What is the main subject discussed in the passage?

A. How to beat a bad mood.           B. How to talk bad moods out.

C. How to do physical exercises.       D. How to join in aerobic exercises.

According to the passage, all of the statements are true EXCEPT that       

climbing is an efficient cure for a bad mood 

B. moods can have a bad effect on people’s health

C. aerobic exercise can help people get rid of bad moods

D. pharmacology has provided people with many tranquilizers

“Feel out of sorts” in paragraph 2 could best be replaced by “        ”

A. put things in order         B. are in high spirits

C. are in a bad mood         D. search for tranquilizers

It can be inferred from the passage that         

A. some drugs are more effective than physical exercises

B. a person does not need aerobic exercise if he is in a good mood

C. the best way to overcome a bad mood is to talk to oneself

D. when in a bad mood, one may not work very efficiently

E
In the atmosphere．carbon dioxide．acts rather like a one-way mirror or the glass in the roof of a greenhouse which allows the sun’s rays to enter but prevents the heat from escaping．
According to a weather expert’s prediction，the atmosphere will be 3°C warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate．If this warming up took place，the ice caps in the poles would begin to melt, thus raising sea level several meters and severely flooding coastal cities．
Also，the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere，possibly resulting in an alteration of the earth’s chief food growing zones．
In the past，concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet．But the weather experts are now paying more attention to West Antarctic，which may be affected by only a few degrees of warming，in other words，by a warming on the scale that will possibly take place in the next fifty  years from the burning of fuels．
Satellite pictures show that large areas of Antarctic ice are already disappearing．The evidence available suggests that a warming has taken place．This fits the theory that carbon dioxide warms the earth．
However, most of the fuel is burnt in the northern hemisphere，where temperatures seem to be falling．Scientists conclude，therefore，that up to now natural influences on the weather have gone beyond those caused by man．The question is：Which natural cause has most effect on the weather?  
One possibility is the variable behavior of the sun．Astronomers at one research station have studied the hot spots and ‘cold’ spots (that is，the relatively less hot spots)on the sun．As the sun rotates，every 27．5 days，it presents hotter or colder faces to the earth，and different aspects to different parts of the earth．This seems to have a considerable effect on the distribution of the earth’s atmospheric pressure，and consequently on wind circulation．The sun is also changeable over a long term：its heat output goes up and down in cycles，the latest trend being downward．
Scientists are now finding shared relation between models of solar weather interaction and the actual climate over many thousands of years，including the last Ice Age．The problem is that
the models are predicting that the world should be entering a new Ice Age and it is not．One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia(惰性)of the earth’s climate．If this is right，the warming effect of carbon dioxide might thus be serving as a useful opposed balance to the sun’s fading heat．
72．It can be concluded that a concentration of carbon dioxide in the atmosphere would ______．
A．mean a warming-up in the Arctic
B．raise the temperature of the earth’s surface
C．prevent the sun’s rays from reaching the earth’s surface
D．explain the cause of great changes in the climate in the northern hemisphere
73．Although the fuel consumption is greater in the northern hemisphere, temperatures there
seem to be falling．This is _______．
A．mainly because the levels of carbon dioxide are rising
B．partly due to changes in the output of solar energy
C．possibly because the ice caps in the poles are melting  
D．only due to the effect of the inertia of the earth’s climate
74．On the basis of their models , scientists are of the opinion that  ________
A．the climate of the world should be becoming cooler
B．the new Ice Age will be delayed by the greenhouse effect
C．the man．made warming effect helps to increase the solar effects  
D．it will take thousands of years for the inertia of the earth’s climate to take effect
75．If the assumption about the delay of a new Ice Age is correct ,  _________     
A．ice would soon cover the northern hemisphere
B．the greenhouse effect could work in favor of the earth
C．the best way to overcome the cooling effect would be to bum more fuels
D．the increased levels of carbon dioxide could warm up the earth even more quickly