тут надо вставить по смыслу

Today the word "electronics" is the general usage.
The center of this world is a tiny silicon plate of a few square millimeters, an integrated circuit, or a chip, as it is more commonly known. The integrated circuit is undoubtedly one of the most sophisticated inventions of man, science and technology. As the operation os an integrated circuit depends on microscopic "components", the purity of all materials and the cleanness at the plant they are produced at must be of the highest quality. 
In the past it took scientists and reserchers a whole lifetime to make a few thousand calculations, whereas for a modern computer this task is a matter of a few seconds. At present computers capable of performing billions of operations a second are required. In the next few years engineers will complete the work on computers of above 2 billion operations a second. It will take a few more years to produce a 10-billion operationscomputer. According to some researchers, we are close to what can be regarded as a true physical limit. But other specialists think that photons will make the operation a thousand times faster. This means that in the future it will be possible to expect the appearance of photon computers and that computations will be done by means of light. In a few decades a new age of light may replace the stil youthful electronic age. The race is going on.

IV.

1. Не watched films at the cinema in June.

2. My aunt listened to music last week.

3. My sister danced at the disco with her friends last Sunday.

4. I visited the zoo with my family in July.

5. My parents helped my granny in the garden in August.

V.

1. Where were you in summer?

2. We usually go to the seaside.

3. We danced at the disco and watched films at the cinema last weekend.

4. He takes his pet for a walk every day.

5. We often help our parents. We cleaned the flat and washed the dishes yesterday.

Test 1.2 I.

Drove, came, flew, ran, was, swam, said, helped, gave, were, watched, took, ate, drank, rode, had, visited, did.