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．
Five Things You Should Know About Adult Asthma (哮喘)
About 44 million people in Asia Pacific suffer from asthma．The numbers are on the rise especially in China and India where there is rapid industrialization and urbanization．Dr Mariko Koh, Director of the Pulmonary Function Laboratory and Asthma Programme at Singapore General Hospital, tells us more about adult asthma:
1．Chronic inflammation (炎症) of the airways
When the airways are inflamed, mucus (粘液) forms, blocking airflow, causing breathlessness, wheezing (喘息) and tightness in the chest.
Exposure to allergens (过敏原) such as mites, cockroaches, pets and pollen can trigger asthma．Tobacco smoke, respiratory infections, exercise and some medications like aspirin and beta blockers are also possible triggers.
Asthma can be controlled with medication．The main treatment of asthma is inhaled(吸入)corticosteroids to reduce inflammation and block of the airways．Reliever medications may be used to treat acute symptoms．Take note: it is not too late to take medication after an asthma attack.
4．Take medication daily
To ensure good control over asthma, medication must be taken daily on a long term basis to prevent attacks．Also, go to your doctor for regular checkups.
5．Quality of life
Asthma sufferers can lead normal active lives as long as the symptoms are well controlled．Taking medication as directed and avoiding triggers can make a big difference to the quality of life.
1．All of the following are possible factors causing asthma except _________.
2．What can be inferred from the passage?
A．There is no possible cure for allergic asthma．
B．Asthma is caused by acute inflammation of the airways.
C．China and India have the largest number of asthma sufferers in the world．
D．Regular checkups and exercise can ensure you a life free from asthma symptoms.
3．The author would most likely to agree that __________.
A．asthma sufferers can lead a normal life as ordinary people
B．daily intake of medication in the long run is helpful in controlling asthma
C．rapid industrialization and urbanization are the leading causes of asthma
D．once asthma attacks, it is too late to take medication
4．What is the purpose of this passage?
A．To explain the cause of asthma
B．To stress the importance of keeping away from asthma
C．To confirm a successful research about asthma
D．To inform readers several aspects about asthma
Getting more followers is something we usually associate with social media or micro messaging apps．But soon we could all have a new type of follower-a robotic one．
Dozens of robots and technology fans gathered in Boston，US，earlier this month for the RoboBusiness conference．The latest developments in the world of robotics were shown to the public and this time the trend was robots following people．
Perhaps the most exciting development on show was the ability of drones（无人机）to follow you from the air，acting as your own personal cameraman or photographer．One example is 3-D Robotics’ Iris+ drone，developed by a US-based company．
The drone is fitted with cameras and has a “follow me” function．It connects with your GPS-enabled Android device（设备），like a mobile phone．Then it flies and follows you around，shooting action footage（影片）of you from above．The soft-ware in the drone makes sure that you’re always in the center of the frame．
It can keep working for 15 minutes，as long as there aren’t too many trees for it to crash into．This could be exciting for anyone who loves action sports or wants to be the star of their own short film．
But what if you want to be one of those celebrities who have helpers carrying all their bags and doing all their chores? A robot called Budgee can help．
Budgee，made by 5 Elements Robotics is literally a basket on wheels．It is mainly designed to help elderly and disabled people．It is also a good choice for anyone who doesn’t have enough arms for grocery bag，Wired magazine reported．It can carry up to 22．7 kg of items．
To make Budgee follow them，its owner will have to wear a small device and use an app to set the distance between themselves and the robot．Budgee even sends a text message when it can’t keep up with its owner．
“I want you to look at the robot like he’s your buddy，he’s your friend．There’s a relationship you develop with the robot，” Wendy Roberts，CEO of 5 Elements Robotics，told gigaom．com．
It might not be quite the same as robotic assistants we’ve seen in movies such as Disney’s Wall-E，where robots cater for (满足)our every need，but that idea doesn’t seem quite so far-fetched(不着边际的) now．
1．The drone developed by a US-based company can_______．
A．decide who to put in the center of the frame
B．fly around you and take videos from above
C．be used to take pictures and make phone calls
D．keep working for 15 minutes in any conditions
2．According to the article，Budgee is most likely to be targeted at_______．
A．staff in supermarkets
B．elderly and disabled people
C．those who love action sports
D．celebrities who need a close buddy
3．The main purpose of the article is to_______．
A．urge people to buy the drone and Budgee
B．tell the reader about two new types of robots
C．call on people to develop relationships with robots
D．analyze why the two types of robots can lead a trend