In the 1880s it was proved that no two people have exactly same                                          【D1】________
fingerprints. It was further discovered that there are four main types of fingerprints.
These four types can be divided to over a thousand smaller groups. In this way fingerprints     【D2】________
can be classified. Therefore fingerprints found at the scene of a crime can be compared with
police records. This comparison used to taking a great deal of time, but now,                            【D3】________
computers make the task much more easier.                                                                                 【D4】________
      Fingerprints can be used for crime prevention as good as crime detection. For example,     【D5】________
someone wanting to open a door at a bank places his or her thumb onto a glass plate in         【D6】________
a special machine. The machine then reads the thumb print, and open the door if it                  【D7】________
matches one on the list of prints of people permitted to enter: Fingerprints are also invaluable
for identifying unknown innocent people. They may be murder and accident victim. They         【D8】________
may be people whom have been found suffering from amnesia(健忘症).                                     【D9】________
      A new way of identifying people is by DNA "fingerprinting". DNA is a natural
chemical substance finding in every cell of the human body.The composition of each               【D10】________
person's DNA is as unique as his or her fingerprints.

【D1】

【D2】

【D3】

【D4】

【D5】

【D6】

【D7】

【D8】

【D9】

【D10】