Look closely at ,your hands-are they clean? It doesn't matter how many times you was  your hands. They're still crowded with microbes, which are also called "germs" or "bacteria". Microbes are everywhere. But don't worry-most microbes don't harm you. and many actually help you stay alive.
Now,  scientists say the microbes that live on our hands could be used in a surprising way: fighting crime.
When police visit the scene of a crime, they often look for fingerprints to try to identifythe criminal.  But according to a recent study, investigators could even use microbes to help break a criminal case.
Every person has his or her own set of microbes that live on their hands, according to scientists at,the University of:Colorado. That means the mix of different kinds of microbes on everybody's hand is unique-much like one's fingerprint.
The scientists wanted to know whether this microbe mix could be used as a new kind of fingerprint-especially in a crime scene where fingerprints might be hard to find.  And policemen use forensics such as studying fingerprints to identify the criminal.
"Microbe fingerprints are harder to hide," said Noah Fierer, one of the scientists.
"You can't sterilize(为……杀菌) a surface just by wiping it off. "
His team compared the bacteria on the hands of 273 people with the bacteria found on each person's computer keyboard. For the study, the keyboards had been used only by the people who were being tested. The study showed that the mix of microbes from each per- son's hands matched the mix of microbes on that person's keyboard. The scientists were easily able to tell the 273 people apart-just by looking at their keyboards.
But there are a lot more than 273 criminals. Other scientists wonder whetherthe microbe fingerprint can really be that useful. 
Fierer agrees that scientists have a lot more work to do before the microbe fingerprint will be a useful tool．
【小题1】According to the passage,  microbes on people's hands_____

 Look closely at your hands--are they clean? It doesn't matter how many times you wash your hands, they're still crowded with microbes, which are also called "germs" or "bacteria". Microbes are everywhere. But don't worry--most microbes don't harm you, and many actually help you stay alive.

Now, scientists say the microbes that live on our hands could be useful in a surprising way: fighting crime.

When police visit the scene of a crime, they often look for fingerprints to try to identify the criminal. But according to a recent study, investigators could even use microbes to help break a criminal case.

Every person has his or her own set of microbes that live on their hands, according to scientists at the University of Colorado. That means the mix of different kinds of microbes on everybody's hand is unique -- much like one's fingerprint.

The scientists wanted to know whether this microbe mix could be used as a new kind of fingerprint -- especially in a crime scene where fingerprints might be hard to find. And policemen use forensics such as studying fingerprints to identify the criminal.

 “Microbe fingerprints are harder to hide,” said Noah Fierer, one of the scientists. “You can't sterilize a surface just by wiping it off.”

His team compared the bacteria on the hands of 273 people to the bacteria found on each person's computer keyboard. For the study, the keyboards had been used only by the people who were being tested. The study showed that the mix of microbes from each person's hands matched the mix of microbes on that person's keyboard. The scientists were easily able to tell the 273 people apart -- just by looking at their keyboards.

But there are a lot more than 273 criminals. Other scientists wonder whether the microbe fingerprint can really be that useful.

Fierer agrees that scientists have a lot more work to do before the microbe fingerprint will be a useful tool.

66．According to the passage, microbes on people's hands         .

       A．do more harm than good

       B．are almost the same

       C．might help solve crimes

       D．are easy to get rid of

67．The underlined word "forensics" in Paragraph 5 probably refers to         .

       A．a new kind of fingerprint

       B．the scientific test used by police

       C．a kind of bacteria in people's hands

       D．a kind of newly invented keyboard

68．What did Fierer's team find through the study?

       A．They could tell who had used which computer．

       B．They found the criminal among the 237 people．

       C．Computer keyboards couldn't keep people's microbe fingerprints

       D．People's hands could be identified by the keyboards they used．

69．We learn from the passage that         .

       A．the microbe fingerprint has been used in many cases

       B．many scientists think microbe fingerprints useless

       C．scientists will come to a clear conclusion soon

       D．your microbes may give you away

70．The passage is mainly about         .

       A．the importance of fingerprints

       B．how to clean our hands

       C．different germs on our hands

       D．the usefulness of microbes

Heroes come in different forms. They are the people who save lives and the people who can stand 36   times. My hero is my mother. When she was diagnosed（诊断）with breast cancer, I was 37  . I didn’t understand how she could appear so healthy 38   a deadly disease existed inside.
My mother went 39  a mastectomy（乳房切除手术）to remove the cancerous cells. For a month after her surgery (外科手术) she was unable to do anything.
It was after this surgery that my mother 40  me the most. Her inactivity really made her  frustrated (沮丧), but she never 41  . She is a strong woman. Unlike some, she never 42  why she had got cancer. Instead, she 43  it and remained optimistic(乐观的).
44   my mother’s illness, I had to step in to do the housework. Previously I would have 45  not to, but I knew this was my 46  .
Those weeks passed slowly but in the end I had a new 47  for my mom. I had never 48  all the things she does on a regular basis. Simple things like cleaning, cooking, laundry and bills really started to become great 49   .
During this special period, I saw the amazing supportive group we have. My parents’ friends couldn’t have done 50   .They stopped by on a regular basis, cooked meals, and supplied us with anything we 51  .They let me know that we will always be there 52   each other.
My mother is healthier now and back to her 53   activities. Our lives are busy but I am a little more willing to 54  around the house. I   55 my mother’s ability to stay optimistic and I only hope that some day I can be lucky enough to be like her.

Heroes come in different forms. They are the people who save lives and the people who can stand 36   times. My hero is my mother. When she was diagnosed（诊断）with breast cancer, I was 37  . I didn’t understand how she could appear so healthy 38   a deadly disease existed inside.

My mother went 39  a mastectomy（乳房切除手术）to remove the cancerous cells. For a month after her surgery (外科手术) she was unable to do anything.

It was after this surgery that my mother 40  me the most. Her inactivity really made her  frustrated (沮丧), but she never 41  . She is a strong woman. Unlike some, she never 42  why she had got cancer. Instead, she 43  it and remained optimistic(乐观的).

44   my mother’s illness, I had to step in to do the housework. Previously I would have 45  not to, but I knew this was my 46  .

Those weeks passed slowly but in the end I had a new 47  for my mom. I had never 48  all the things she does on a regular basis. Simple things like cleaning, cooking, laundry and bills really started to become great 49   .

During this special period, I saw the amazing supportive group we have. My parents’ friends couldn’t have done 50   .They stopped by on a regular basis, cooked meals, and supplied us with anything we 51  .They let me know that we will always be there 52   each other.

My mother is healthier now and back to her 53   activities. Our lives are busy but I am a little more willing to 54  around the house. I   55 my mother’s ability to stay optimistic and I only hope that some day I can be lucky enough to be like her.

1.                A．present         B．short           C．boring    D．hard

2.                A．shocked        B．discouraged     C．disappointed   D．hurt

3.                A．but            B．though         C．while D．since

4.                A．up            B．through         C．away     D．off

5.                A．worried        B．impressed       C．benefited from D．depended on

6.                A．complained     B．minded         C．moved   D．spoke

7.                A．questioned      B．explained       C．understood    D．learned

8.                A．welcomed      B．received        C．changed  D．accepted

9.                A．As well as       B．Because of      C．In case   D．As a result

10.               A．begged         B．refused        C．decided   D．pretended

11.               A．chance         B．turn           C．luck  D．responsibility

12.               A．respect        B．opinion         C．gift   D．job

13.               A．thought        B．known         C．realized   D．understood

14.               A．lessons         B．pleasures       C．troubles   D．experiences

15.               A．all             B．nothing         C．less  D．more

16.               A．dreamed       B．knew          C．needed   D．borrowed

17.               A．from           B．for            C．against    D．without

18.               A．interesting      B．often          C．busy  D．normal

19.               A．work out       B．set out         C．look about D．help out

20.               A．treasure        B．respect         C．admire    D．admit

Below is a selection from a popular science book.
If blood is red, why are veins（静脉） blue?
Actually, veins are not blue at all. They are more of a clear, yellowish color. Although blood looks red when it’s outside the body, when it’s sitting in the vein near the surface of the skin, it’s more of a dark reddish purple color. At the right depth, these blood-filled veins reflect less red light than the surrounding skin, making them look blue by comparison.
Which works harder, you heart or your brain?
That kind of depends on whether you’re busy thinking or busy exercising. Your heart works up to three times harder during exercise, and shifts enough blood over a lifetime to fill a supertanker. But in the long run, your brain probably tips it, because even when you’re sitting still your brain is using twice as much energy as your heart, and it takes four to five times as much blood to feed it.
Why do teeth fall out, and why don’t they grow back in grown-ups?
Baby (or “milk”) teeth do not last long; they fall out to make bigger room for bigger, stronger adult teeth later on. Adult teeth fall our when they become damaged, decayed and infected by bacteria. Once this second set of teeth has grown in, you’re done. When they’re gone, they are gone. This is because nature figures you’re set for life, and what controls regrowth of your teeth switches off.
Do old people shrink as they age?
Yes and no. Many people do get shorter as they age. But, when they do, it isn’t because they’re shrinking all over. They lose height as their spine（脊柱） becomes shorter and more curved due to disuse and the effect of gravity(重力). Many (but not all) men and women do lose height as they get older. Men lose and average of 3-4 cm in height as they age, while women may lose 5 cm or more. If you live to be 200 years old, would you keep shrinking till you were, like 60 cm tall, like a little boy again? No, because old people don’t really shrink! It is not that they are growing backwards ----- their legs, arms and backbones getting shorter. When they do get shorter, it’s because the spine has shortened a little. Or, more often, become more bent and curved.
Why does spinning make you dizzy（眩晕的）?
Because your brain gets confused between what you’re seeing and what you’re feeling. The brain senses that you’re spinning using special gravity-and-motion-sensing organs in your inner ear, which work together with your eyes to keep your vision balance stable. But when you suddenly stop spinning the system goes out of control, and your brain thinks you’removing while you’re not.
Where do feelings and emotions come from?
Mostly from an ancient part of the brain called the limbic system. All mammals have this brain area ----- from mice to dogs, cats, and humans. So all mammals feel basic emotions like fear, pain and pleasure. But since human feelings also involve other, newer bits of the brain, we feel more complex emotions than any other animal on this planet.
If exercise wears you out, how can it be good for you?
Because our bodies adapt to everything we do to them. And as far as your body is concerned, it’s “use it, or lose it”! It’s not that exercise makes you healthy, it’s more that a lack of exercise leaves your body weak and easily affected by disease
【小题1】What is the color of blood in a vein near the surface of the skin?