Wi-Fi is a wireless networking technology used across the globe. A 1 misunderstanding is that the term Wi-Fi is short for “wireless fidelity(保真度)”. However, this is not the case. Wi-Fi is 2 a trademarked phrase that uses the 802.11 standard, which was 3 by the Institute of Electrical and Electronics Engineers (IEEE). That is to say, instead of using 4, your computer is connected to the internet or other computers by radio.

    This standard was 5 promoted by the Wi-Fi Alliance, a trade group that pioneered commercialization of the 6. A person or business can use a wireless router( 路由器) or a similar 7 to create a “hotspot” or an area in which proper devices can connect wirelessly to a network or 8 Internet access. This router is usually connected to the Internet by 9 of a modem, often one   10 as a high-speed connection. Any user within about 200 feet of the 11 point can then connect to the Internet, 12 for good transfer rates, distances of 100 feet or less are often suggested. Salespersons also sell signal boosters（放大器）that  13 the range of a wireless network.

    Wi-Fi networks can either be 14 or closed, in which case a 15 is needed. An area blanketed in wireless access through a device is often called a “wireless 16.” Anyone with a device that  17 proper functionality can connect to this network while in the hotspot. Through this connection, a 18 network can be accessed or Internet connectivity can be achieved. This allows people within the hotspot to connect to the Internet via the router and modem, often 19 for employees at a business or as a free 20 at coffee shops and similar locations.

    Since 2007, the American Psychological Association (APA) has conducted a survey of different aspects of stress in America. This year's analysis focused on teens, and on a 10 point scale, adolescents ranked their stress at 5-8, compared with a score of 5-1 reported by adults.

    “What is even more disturbing,” says Norman Anderson, CEO and executive vice president of the APA, “is the fact that most teens knew their stress levels weren't healthy—they said 3-9 was probably more desirable—but did little about it.” In fact, the survey revealed that 42% of teens aren't doing enough to manage their stress.

    The researchers were concerned about it, since unaddressed stress can lead to both short-term mental-health issues such as depression, as well as lay the seeds for long-lasting conditions such as heart disease, diabetes, and high blood pressure in adulthood.

What's causing teens to feel so anxious? Eighty three percent cited school as a source of stress, including concerns about their future after high school and worries about college. For some, family financial issues also caused anxiety, which wasn't surprising since previous studies found that parental stress can pass down onto children, even at very young ages.

    “This branch of population is not taken seriously sometimes,” said Katherine Nordal, of the APA, “we wanted to shine light on some of the problems we know teens are having and whether they are successful at coping with them or not.”

    “Clearly,” said Anderson, “we have work to do to manage stress overall. Stress levels among Americans continue to be high, but coping mechanisms(机制) remain ineffective,” Teens reported doing everything that they probably shouldn't in order to relieve stress—they aren't getting enough sleep, which can add to anxious feelings, and they're less physically active. Exercise is among the best ways to reduce stress, but the survey found that teens were beginning to rely on sitting activities, such as surfing the internet, engaging in social media or watching videos, to relieve stress.

    First aid is of importance in our life. There is no doubt  it is necessary to know some knowledge of first aid as dangers lie everywhere and  (accident) happen from time to time. If a person has an accident, he needs medical care  a doctor can be found. But in the process of first aid, whether the    (injure) will be properly treated depends on your knowledge of first aid. As  famous journalist, Yansong leads a very simple life. But he not only has a good nose for news, but also has (admire) professional first aid skills, because he (think) if we know something about first aid, perhaps a life can (save).

    Everybody should know some first aid in order to save other (people) lives. Let's take delight in  (acquire) skills of first aid.

增加：在缺词处加一个漏字符号(∧)，并在其下面写出该加的词。

删除：把多余的词用(＼)划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1.每处错误及其修改均仅限一词；

      2.只允许修改10处，多者（从第11处起）不计分。

    As the saying goes, “many little drop of water make an ocean.” A small action may lead to major changes in society. My friends and I participated a voluntary activity at a nursing home last week. We first did some cleaning or washing. After that we spend half an hour chat with the old people living there. Though it was a tired day, we were happy with that we did. I felt a sense of responsibility by visiting the old. If all of us lend a helping hand to the people in the need, we can live in harmony with each other. A society is just like a family. If they are willing to help others, our small action can make a bigger difference.

1. “绿色食品”的现状；

2. 这种现象产生的原因；

3. 你的看法。

注意：

1. 词数100左右；

2. 可以适当增加细节，以使行文连贯。