Question

 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

Answer 1

BDBAC