Wolf in sheep's clothing is an idiom of Biblical origin. It is used of those playing a role contrary to their real character, with whom contact is dangerous. As a fable it has been falsely credited to Aesop and the theme is now numbered 451 in the Perry Index. The confusion has arisen from the similarity of the theme with fables of Aesop concerning wolves that are mistakenly trusted by shepherds; the moral drawn from these is that one's basic nature eventually betrays itself.

Mobile phones have changed people's lives. They give us an opportunity to stay in touch and to be reachable everywhere. If you are going to be late, you can just call your relatives, friends or colleagues or send them a text message. It is very easy and comfortable, especially for the busy modern lifestyle. So a mobile phone has become a vital part of our daily lives and it is difficult to imagine how people lived without mobile phones in the past.
The modern mobile phone is a more complex version of the two-way radio which was a very limited means of communication. As soon as the callers moved out of range of each other's broadcast area, the signal was lost. In the 1940s, scientists began using a number of radio masts located around the countryside to pick up signals from two-way radios. A user would always be within range of one of the masts. If he moved too far away from one mast, the next mast would pick up the signal. Scientists called each mast's reception area a separate 'cell'; this is why mobile phones are also called 'cell phones'.
However, 1940s technology was still quite primitive, and the 'telephones' were enormous boxes which had to be transported by car. In 1973 Dr Martin Cooper invented the first practical mobile phone for handheld use in a non-vehicle setting. Using a modern, if somewhat heavy portable handset, Cooper called his rival, Dr. Joel S. Engel, to announce his success.
Until the early 1990s, most mobile phones were too large to be carried in a pocket, so they were typically installed in vehicles as car phones. Since digital components became miniature and more sophisticated batteries were developed, mobile phones have become smaller and lighter. So the large plastic bricks of the 80s turned into smooth little objects that could be put into pockets and bags. In the mid-90s almost everyone had a mobile phone.
Over the last few years mobiles have become more and more advanced. Modern mobile phones may support many additional services, and accessories, such as SMS, email, packet switching for access to the Internet, gaming, Bluetooth, personal organiser, camera with video recorder, MMS for sending and receiving photos and video, MP3 player, radio, GPS navigation, etc.
Nowadays the mobile phone is often called the Fourth Screen (after cinema, TV and PC screens as the first three). It is also called the Seventh of the Mass Media (with Print, Recordings, Cinema, Radio, TV and Internet as the first six).
The most commonly used data application on mobile phones is Short message service (SMS). It is a wireless service that enables to send and receive short messages to and from mobile telephones. It is interesting to know that the first SMS text message was sent from a computer to a mobile phone in 1992 in the UK, while the first person-to-person SMS from phone to phone was sent in Finland in 1993. SMS messages have a number of advantages. Firstly, SMS is a rather cheap and quick method of communication. Secondly, SMS messages are non-intrusive. In comparison with a call they do not interrupt a person if he or she is in the middle of a meeting and can't answer you right now.
The 160-character limit on text messages has led to a new, abbreviated version of English similar to a rebus. There are no standard rules for writing SMS messages, and a lot of words can be shortened. Sending SMS messages can be time consuming. The objective of SMS is to convey a comprehensible message as quickly as possible. That is why traditional rules of grammar, spelling and punctuation are largely ignored when you are hurriedly typing to your friend that you are going to be late.
Some people say that mobile phones deprive them of privacy and it is almost impossible to have a rest with your mobile phone on. Many people are also worried about the harmful influence of mobile phones on their health. Mobile phones use electromagnetic radiation in the microwave range. Scientists persuade that there is no significant health effect from mobile phone radiation. But still it is better not to use your mobile phone too often.

Dr Kim says
Dr KimMobiles are a great way to communicate but they can be a nuisance to you and others around you. You can leave a message that you are busy and then switch it to off or silent so that you can catch up when you have time. 
Dr KateMobiles can be very expensive and some kids have got huge bills because they didn't really understand the charges. Your parents or caregivers are responsible for the bills so make sure that you are doing the right thing or you could be the only kid in your group without a mobile…for a very long time! Having a phone card is a good way to go because if you run out of credit that's it!

The technical progress goes straight in huge steps. Nowadays we dispose of different machines which surround us everywhere. One of them is a mobile phone. But does it actually make our life better?

The most important advantage of mobile phones is that you can simply talk to any person wherever you are. As a result you should to bother, for instance, about your relatives. Moreover you are always available to delay meetings or let somebody know if you are late. In addition mobile phones can help fill in your free time. For example you might play games on it while waiting for the flight.
Nevertheless using this kind of gadgets has its own drawbacks. First of all it has bad influence on health. Some statistics claim that if you place three phones round the egg and start calling about five minutes, this egg will be cooked. Different scientists tell us about harm of phones to our hearts, lungs and other organs.
All in all, though this wonder of engineering has bad sides we definitely could not deny its huge profits. Try to find someone who dares to throw his phone away. I find this mission impossible.

At present mobile phones have become ingrained in our everyday lives and the majority of people can hardly imagine themselves without cell phones. Is it just a tribute to fashion or a necessity of a modern person?
It isn’t a secret that today many people feel quite helpless if they have leaft their mobile phones at home. First of all cell phones give us an opportunity to keep in touch with people in any place and in any time (it’s especially important for businesspeople). Besides, modern mobile phones are multi-function: they provide access to the Internet, have various games, cameras, memory sticks, etc.
Nevertheless we can’t deny that mobile phones provoke a range of problems. People have started to see each other less frequently. Mobile communication requires quite a lot of money and people have to control the amount of money on their accounts constantly otherwise at the most inappropriate moment they won’t be able to phone the people they need. But the greatest disadvantage of cell phones is certainly their harmful influence on people’s health.
In my opinion at the present time mobile phones are an integral part of life of any person and we can’t stop it. I personally need it everyday for my work and to keep in touch with my friends and relatives, though I’m aware of its deleterious influence on my health. But I try to avoid idle talks on the phone to reduce the influence of harmful radio waves. I try to find the happy mean.

Essay:
Mobile phone mostly is one of the latest inventions in modern life. It brings many conveniences for public in many fields of life. It gradually makes people change the way to communicate as well as consider it as something on their person.
Nowadays, mobile phone makes the communication among people very different from what in the past. Face- to-face communication becomes an old-fashion in modern life because it is not convenient and takes a lot of time. Instead, mobile phone helps conversations occur fast and correctly. Besides, people can get information from another in any places like in a car, on the street, in subway, etc. Moreover, in some emergency situations, mobile phones are considered as the most useful tool to solve problem. For example, when an accident happened on the street, people can use cell phone to call ambulance and inform the place of accident to policeman.
Because of the convenience of mobile phones, no doubt that it now becomes a popular tool of every person. Modern life requires everything to happen fast and immediately. As a result, people cannot almost live without cellphone. Besides, mobile phone nowadays is not only a useful tool for human lives, but also the way for people to show off. Everyday, various kinds of mobile phones are produced to adapt the orders of people. More and more functions like multi-media, camera, even the Internet which all have in a mobile phone. Hence, people can use mobile phone for many purposes instead of hear and call like in the past.
However, it is a reality that advantages and disadvantages are like both sides of a coin, so as any other thing, mobile phone also has some downsides. For example, people are going to face some deseases which come from using mobile phones like deaf and loud-noise syndrome. On the other hands, people are losing ability of face- to-face communication. I think these are two reasons that make some people do not like to adapt this kind of communication.
To sum up, I think mobile phone plays an important role in our lives. It brings us many benefits. Although it causes some disadvantages for us but these are too small in comparison with what it has created in modern life.

From children to senior citizens, mobile phones have become a craze as a way of staying ahead with the technology. With our fast lifestyles, we have no time to meet our relatives or friends and are left with the only option of talking over the phone. Here comes the need of mobile phones, which allow us to stay connected wherever we are and whenever we need to.
Everybody today owns at least a basic mobile phone. What makes it easy to use is its user-friendly nature, small size and its numerous attractive features. However, people are always eager to replace their mobile phones with the latest models having more advanced features. As the technology is scaling new heights, mobile phones are becoming cheaper and cheaper and the customer is getting more for less. A great way of amusing yourself is by playing games on your mobile phone. If you want to store your precious moments, you can use its video recording feature. Mobile phones can become expressions of who we are by getting mobile ringtones, wallpapers, which turn your phone into a unique device.
Whatever may be said against mobile phones their advantages have always scored over their disadvantages. They have proved useful for every purpose. Nothing is as comfortable as a mobile phone for communicating over a distance. You cannot be present at the same time at more than one place, but if required you can just make use of your mobile phone and get your work done. Mobile phones have definitely become the most vital part of our lives. It is hard to imagine life without mobiles. Indeed, mobile phones keep you connected round the clock. They are now inexpensive, easy to use, comfortable and equipped with almost every latest feature you desire. Today, a technologically advanced mobile phone can perform as many tasks as well as that of a personal computer. Even remote countries have started having mobile phone services.