Passenger pigeons (旅鸽) once flew over much of the United States in unbelievable numbers．Written accounts from the 18th and 19th centuries described flocks (群) so large that they the sky for hours．
It was calculated that when its population reached its highest point, they were more than 3 billlion passenger pigeons—a number equal to 24 to 40 percent of the total bird population in the United States, making it perhaps the most abundant bird in the world．Even as late as 1870 when their numbers had already become smaller, a flock believed to be 1 mile wide and 320 miles (about 515 kilometers) long was seen near Cincinnati．
Sadly the abundance of passenger pigeons may have been their undoing．Where the birds were most abundant, people believed there was an ever-lasting supply and killed them by the thousands．Commercial hunters attracted them to small clearings with grain, waited until pigeons had settled to feed, then threw large nets over them, taking hundreds at a time．The birds were shipped to large cities and sold in restaurants．
By the closing decades of the 19th century, the hardwood forests where passenger pigeons nested had been damaged by American’s need for wood, which scattered (驱散) the flocks and forced the birds to go farther north, where cold temperatures and storms contributed to their decline．Soon the great flocks were gone, never to be seen again．
In 1897, the state of Michigan passed a law prohibiting the killing of passenger pigeons, but by then, no sizable flocks had been seen in the state for 10 years．The last confirmed wild pigeon in the United States was shot by a boy in Pike County, Ohio, in 1900．For a time , a few birds survived under human care．The last of them, known affectionately as Martha, died at the Cincinnati Zoological Garden on September 1, 1914．
1．In the 18th and early 19th centuries, passenger pigeons _______．
A．were the biggest bird in the world
B．lived mainly in the south of America
C．did great harm to the natural environment
D．were the largest bird population in the US
2．The underlined word “ undoing” probably refers to the pigeons’ _______．
A．escape B．ruin C．liberation D．evolution
3．What was the main reason for people to kill passenger pigeons?
A．To seek pleasure． B．To save other birds．
C．To make money． D．To protect crops．
4．What can we infer about the law passed in Michigan?
A．It was ignored by the public． B． It was declared too late．
C．It was unfair． D．It was strict．
New crime prediction software should reduce not only the murder rate, but the rate of other crimes. Developed by Richard Berk, a professor at the University of Pennsylvania, the software has already used in Baltimore and Philadelphia to predict which individuals on probation(缓刑) or parole(假释) are most likely to murder and to be murdered.
“When a person goes on probation or parole he is supervised(监督) by an officer. The question is ‘what level of supervision is appropriate?’” said Berk. It used to be that parole officers used the person’s criminal record, and their judgment to make decisions.
“This research replaces those seat-of-the–pants calculations,” he said.
Technology helps determine level of supervision. On average there is one murder for every 100,000 people. Even among high-risk groups the murder rate is one in 100. Predicting such a rare event is very difficult, but advances in computer technology works.
Years ago, the researchers made a dataset of more than 60,000 various crimes. Using the software they developed, they found some much more likely to commit murder when paroled or probated. They could identify eight future murderers out of 100.
Berk’s software examines roughly two dozen variables(可变因素), from criminal record to geographic location. The type of crimes, and more importantly, the age at which that crime was committed, were two of the most predictive variables.
“People assume that if someone murdered then they will murder in the future,” said Berk. “ What really matters is what that person did as a young individual. Predicting future crimes sounds well. But we aren’t anywhere near being able to do that.”
“Berk’s scientific answer leaves policymakers with difficult questions. By labeling one group of people as high risk, and supervise them closely, there should be fewer murders, which the potential victims should be happy about. It also means that those high-risk individuals will be supervised more aggressively. For human rights advocates, that means punishing people who, most likely, will not commit a crime in the future,” said Bushway. “It comes down to a question of whether you would rather make these errors or those errors.”
1．The underlined words(in Para.3) probably mean_______.
A．calculations based on subjective opinions
B．calculations based on widespread voting
C．calculations made by advanced technology
D．calculations based on serious considering
2．For 650 people with crime records, how many potential murderers would the software find?
A．6.5. B．13. C．52. D．65.
3．From Para 7, we can infer that______.
A．the technology developed by Richard Berk will soon be widely used in the US
B．the technology would not be widely accepted in the short term
C．whether a person murders or not largely decided by his upbringing while young
D．if a person murdered when he was fifty, he is sure to murder again while on probation
4．Bushway’s attitude to the technology put forward by Richard Berk is _______.
A．positive B．negative C．objective D．indifferent
5．Which would be the best title for the passage?
A．Closely Supervise Potential Murders
B．Measures Taken to Prevent Criminal Behavior
C．Technology Revolutionizes Judges’ Way of Working
D．Software is Developed to Predict Criminal Behavior
Security—for the information on your smartphone, as well as for the phone itself---is a hot topic these days．The truth is that you’re packing a lot of sensitive information on your phone, and you should keep it safe．
When it comes to physical security, iPhone users would do well to download Find My iPhone, a free app from Apple that allows you to visit a website and see your (lost, stolen or misplaced) phone on the map．You can then sound an alarm, send a message that will pop up on its screen, lock the phone or erase all your data．
Android does not have an exact equivalent(等价物), but there are plenty of alternatives．A free app called Lookout offers the find-my-phone feature．The paid version allows you to wipe the data from your phone remotely．
Then there is your coffee shop’s WiFi network．Anyone with minimal technical expert skill can snoop on(窥视) people using shared wireless networks, harvesting passwords and other personal data．Lookout’s apps will caution you when you’ve logged on to an insecure network, but cannot protect you once you’re there．
In order to protect yourself on such networks, you can use a virtual private network, or V．P．N．This turns all your activity into nonsense to anyone trying to read along with you from across the Starbucks．It also keeps websites from tracking you and, if you’re traveling, allows you to get access to sites that may be blocked in other countries．
If you have an iPhone, the simplest V．P．N．app is probably Hotspot Shield, whose distinguishing feature is said to be that it automatically kicks in each time you start browsing (浏览), as opposed to other V．P．N．apps that require you to start them up manually(手动)．This matters, because even if you decide you want a V．P．N．app, you want to spend approximately zero time thinking about it．For the most part, that was true of Hotspot Shield, though occasionally it took a while to connect or temporarily lost connection without warning．I found myself having to turn the app on and off sometimes, which involved setting my phone constantly．
If even reading about the setting on your phone drives you crazy, then it is probably best to stay away from a V．P．N．app．But if you’re the type who can’t resist checking your bank balance from your comer bar, the hassle (麻烦) may be preferable to the risk．
1．Which of the following can warn you against the insecure network?
A．Android B．V．P．N． C．Lookout D．Find My iPhone
2．By using V．P．N．, users can ________．
A．find their lost phone on the Internet
B．remove all the data form the phone remotely
C．check the bank balance now and then
D．save their browsing from being tracked
3．The underlined word “that” in Para．6 refers to the fact that _________．
A．a V．P．N．app kicks in automatically
B．the users starts V．P．N．apps manually
C．the app take a while to connect
D．users spend no time thinking about it