1. No city has cables _______laid____ directly. a. lay b. are laying c. laid 2. Computers _____are used______ to perform series of mathematical operations. a. are used b. are using c. have used 3. ____To reduce_______ power los...

1. No city has cables _______laid____ directly. a. lay b. are laying c. laid 2. Computers _____are used______ to perform series of mathematical operations. a. are used b. are using c. have used 3. ____To reduce_______ power losses, thick wires should be used. a. Reducing b. To reduce c. Having reduced 4. For information __transmitted_________, it must be attached to a radio – frequency carrier wave. a. to be transmitted b. will be transmitted c. transmitted 5. Various installations _have been used__________ to transform electric power into mechanical and heat power. a. have been used b. are using c. are being used 6. The experiment ___________ to be continued . a. reports b. is reporting c. is reported 7. A computer ___________ to possess four main parts. a. has been known b. is known c. knows 8. The atmosphere ___________ to extend several hundred kilometers above the Earth. a. proves b. has been proved c. is proved 9. Transistor batteries ___________ to be used in systems that have to operate on weak signals, for example, in ultra-long-distance space communications. a. expected b. have been expected c. were expected 10. Materials ___________ very high resistance are called insulators. a. having b. have c. are having