填空题

Next time you enter a username and password, think about the rhythm of your typing. Not only can it be used to identify you, it can reveal if you are in a stressful environment.
It has long been known that the rhythms of a person’s typing style are (47) over time, leading to suggestions they could be used to (48) identity or even spot early signs of Alzheimer’s disease. But little was known about the effect of stress on typing (49) , so psychologist Mike Dowman and colleagues at the University of Abertay investigated.
They asked 35 people to log into a computer 36 times over three (50) sessions up to a month apart, using the same username and password. People were put into (51) and relaxed states alternately(交替地) by listening to a range of sounds known to (52) particular emotions.
The length of time each key was held down and the (53) between one being released and another pressed was recorded to generate a typing "fingerprint" for each person. The team used the data to develop and test software that identifies a person from their typing style (54) .
The data also showed that stress can be (55) in a person’s typing because it changes the pattern of timings.
"There’s no question: people do type (56) under stress," says Dowman. He suggests that security systems could be designed to raise the alarm if it seems that a person might be being forced to log into a system. More research will be needed, however, before a system could tell if a person is, say, just having a bad day or being held at gunpoint.

• A) stressed
• B) alone
• C) provoke
• D) stable
• E) interval
• F) verify
• G) only
• H) unchangeable
• I) differently
• J) environments
  K) detected L) complete M) normally N) patterns O) separate