"To be" and its functions. "To have" and its functions

III. Make the following sentences negative and interrogative and translate them:

1. 
   There are various kinds of electric current here.
   
2. 
   There is an electric current in that conductor.
   
3. 
   There is a trouble in the main line.
   
4. 
   There are some orbits in this is atom.
   
5. 
   There are five main parts in this complicated device.
   

IV. Put the sentences in the Past and Future Simple Tense:

1. 
   There are many types of computers.
   
2. 
   An electronic computer is a large complex device.
   
3. 
   There are some kinds of electron tubes in use.
   
4. 
   A capacitor is one of the main elements of a circuit.
   
5. 
   The function of insulators is to isolate the metal plates and to prevent a short.
   
6. 
   The most common meters are the ohmmeter, the voltmeter, and the ammeter.
   

2. “To have” and its functions.

1. 
   Ask all possible kinds of questions:
   

1. 
   All substance have some ability to conduct the electric current.
   
2. 
   A modulated current has variable amplitude.
   
3. 
   An electronic computer has five main parts.
   
4. 
   A pentode has two electrodes and three grids.
   
5. 
   That cubic lattice has atoms at the corners and at the centre of the cube.
   
6. 
   Variable capacitors have air insulators.
   
7. 
   When a capacitor has a trouble it does not store energy.
   

II. Give short answers to the following questions:

1. 
   Do electrical devices have a wide application in every house?
   
2. 
   Do triodes have their greatest use as amplifiers?
   
3. 
   Does the current flowing in the circuit have a steady value?
   
4. 
   Do generators have an armature and an electromagnet?
   
5. 
   Did you have a seminar yesterday?
   
6. 
   Will you have every opportunity to master your knowledge?
   
7. 
   Did they have any transformers in the system to reduce the
   

voltage?

8. 
   Do these machines have an automatic program?