1. Frequencies ranging from 300 to 3000 kilohertz are referred to as medium radio frequencies.
а) Participle I в функции определения
2. The alternating (а) Participle I в функции определения )current passes through a winding on a permanent magnet, causing (б) Participle I в функции обстоятельства) the magnetic field.
3. The seven digits are transmitted to the exchange by appropriate dialing.
г) герундий
4. At the moment we are using a modem linked up direct to our computer and the telephone line.
в) Participle I в составе временной группы Continuous
2. buy - обычно -Present Simple
3. is drinking - сейчас -Present Continuous
4. are walking - сейчас -Present Continuous
5. is laughing - сейчас -Present Continuous
6. is playing - сейчас -Present Continuous
7. wear -обычно -Present Simple
8. eats -обычно -Present Simple
9. are sleeping - сейчас -Present Continuous
10. do you go -обычно -Present Simple
11. never eat -обычно -Present Simple
12. don't like -обычно -Present Simple
13. are you doing - сейчас -Present Continuous
14. is walking - сейчас -Present Continuous