Определите функцию слов заканчивающихся на ing:
а) Participle I в функции определения;
б) Participle I в функции обстоятельства;
в) Participle I в составе временной группы Continuous;
г) герундий.

1. Frequencies ranging from 300 to 3000 kilohertz are referred to as medium radio frequencies.
2. The alternating current passes through a winding on a permanent magnet, causing the magnetic field.
3. The seven digits are transmitted to the exchange by appropriate dialing.
4. At the moment we are using a modem linked up direct to our computer and the telephone line.