II/ Read and answer the following questions

       A mobile phone, also known as cell phon, is one that we can use to make telephone calls to anyone from a great distance via a radio link. Apart from telephony, modern mobile phones also support a number of other services inclding text messaging, internet access, gaming, photography, and many business applications.

       The first cell phone weighed about 2 kilograms and was demonstrated in 1973 by Dr. Martin cooper and John F. Mitchell of Motorola .Ten years later, in 1983, the first of cell phone went on sale to the public. By 2011, over six billion people, 87% of the world’s population, used mobile networks.

        In spite of the many advantages a cell phone has, it also brings about several problems that users should be awared of. Mobile phone radiation is believed to be harmful to human health.

1. When was the first cell phone demonstrated?

2. How many percents of the world’s population did use mobile networks by 2011?

3. Is mobile phone radiation believed to be harmful to human health?

4. What services do modern smart mobile phones support?

5. Should students be allowed use cell phone at school? Why/why not?